This is a tracking issue for deprecation warnings for breaking changes in v5. The list can be updated with https://cijbg.csb.app/ which also helps identifying missing deprecation warnings.

If you see issues with individual items please open a separate issues (otherwise the conversation will be hard to follow since GitHub has no threading).

List of breaking changes

A checked checkbox means we have a deprecation warning, unchecked means no deprecation warning and line-through means there's a rationale why we don't intend to add one.
Paste below list source back into https://cijbg.csb.app/ to have it updated.
WARNING: DO NOT MANUALLY CHECK ITEMS. ONLY STRIKETHROUGH WITH A RATIONALE IS ACCEPTED

• [core] Remove makeStyles from @material-ui/core

• [theme] Remove MuiThemeProvider alias - there was already deprecation in place (https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/styles/MuiThemeProvider.js)

• [withWidth] Remove API

• [core] Remove styled from @material-ui/styles in core

• [core] Remove withTheme from @material-ui/core

• [Select] Remove labelWidth prop

• [theme] Remove theme.breakpoints.width helper
  deprecated in #25993

• [theme] Remove theme.typography.round helper
  deprecated in #25916

• [ButtonBase] Remove buttonRef prop
  deprecated in #25897

• [theme] Remove fade color helper
  deprecated in [theme] Deprecate fade color utility in favor of alpha #22837

• [core] Drop support for node 10

• [types] Bump minimum required TypeScript version to 3.5

• [system] Use spacing unit in gap, row-gap, and column-gap

• [ ] [CssBaseline] Change body font size to body1 (1rem)
  Change of default, can't be deprecated.

• [Icon][SvgIcon] Change default fontSize from default to medium
  deprecated in #23971

• [system] Make borderRadius multiply a theme's design token

• [Dialog][Modal] Remove disableBackdropClick
  deprecated in #24081

• [ ] [TextField] Change default variant from standard to outlined
  Change of default prop, can't be deprecated.

• [system] Remove css utility in favor of sx
  deprecated in #23480

• [withMobileDialog] Remove HOC
  deprecated in #23570

• [ ] [InputBase] Use ref prop instead of inputRef prop on input component
  Not worth the effort, there is already a warning (handleInputRefWarning) that tests that the ref is correctly forwarded, it should be enough once developers upgrade.

• [ ] [AvatarGroup] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [Table] Rename onChangeRowsPerPage, onChangePage
  deprecated in #23789

• [ ] [Pagination] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [theme] Rename fade to alpha
  deprecated in #22837

• [ ] [Accordion] Remove display:flex from AccordionDetails
  CSS change, we can't deprecate

• [ ] [ToggleButton] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [ ] [SpeedDial] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [ ] [Skeleton] Move from lab to core

• [ ] [Rating] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [ ] [Autocomplete] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [ ] [theme] Rename type to mode
  Handled with the adaptV4theme() helper

• [ ] [Alert] Move from lab to core
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [ ] [Autocomplete] Get root elements of options via renderOption
  Lab component, the component is reexported until 5.1.0 with a deprecation message.

• [Accordion] Normalize focusVisible logic
  deprecated in #24083

• [ ] [Stepper] Remove Paper and built-in padding
  We can't introduce a deprecation.

• [ ] [Rating] Use different shape for empty and filled icons
  We can't introduce a deprecation.

• [ ] [theme] Always return default spacing value with px units
  We can't introduce a deprecation.

• [ ] [theme] Remove palette.text.hint key
  Handled with the adaptV4theme() helper

• [core] Remove onRendered from Modal and Portal
  deprecated in #24082

• [ImageList] Refactor using CSS grid & React context
  deprecated in #22363

• [ImageList] Rename Tile to Item
  deprecated in #22363

• [ ] [Tooltip] Make interactive default
  Change of default prop, can't be deprecated.

• [ ] [theme] Rename theme keys to defaultProps and styleOverrides
  Handled with the adaptV4theme() helper

• [GridList] Rename to ImageList
  deprecated in #22363

• [ ] [docs] Fix @global being considered a class
  It's for the docs, no need to worry about it.

• [ ] [Theme] Restructure component definitions
  Handled with the adaptV4theme() helper

• [Menu] Remove transition onX props
  deprecated in #22213

• [Popover] Remove transition onX props
  deprecated in #22202

• [ ] [TrapFocus] Entangle effects
  It's a bug fix, that changes the behavior.

• [ ] [TextField] Remove line-height reset
  It's a bug fix, that changes the behavior.

• [Dialog] Remove transition onX props
  deprecated in #22114

• [theme] Remove theme.mixins.gutters
  deprecated in #22245

• [Snackbar] Remove transition onX props
  deprecated in #22206

• [ ] [useIsFocusVisible] Remove focus-visible if focus is re-targetted
  It's a bug fix, that changes the behavior.

• [CircularProgress] Remove static variant, simplify determinate
  deprecated in #22094

• [ ] [Skeleton] Rename variant circle -> circular and rect -> rectangular for consistency
  Components in the lab do not need deprecation as they were perpetual alpha.

• [Badge] Rename overlap circle -> circular and rectangle -> rectangular for consistency
  deprecated in #22076

• [Avatar] Rename variant circle -> circular for consistency
  deprecated in #22090

• [ ] [Pagination] Rename round -> circular for consistency
  Components in the lab do not need deprecation as they were perpetual alpha.

• [ ] [TextField] Better isolate static textarea behavior to dynamic one
  Already had deprecation in place.

• [ ] [Snackbar] Change the default position on desktop
  We can't deprecate.

• [RootRef] Remove component
  deprecated in #24075

• [ ] [List] Improve hover/select/focus UI display
  Unclear what a deprecation for changed styles should look like

• [Accordion] Add new classes key
  deprecated in #24084

• [Fab] Rename round -> circular for consistency
  deprecated in #24080

• [TextareaAutosize] Rename rowsMax->maxRows & rowsMin->minRows
  deprecated in #23530

• [core] Remove /test-utils
  deprecated in #24099

• [Grid] Rename justify prop to justifyContent
  deprecated in #24078

• [ ] [core] Drop support for non-ref-forwarding class components
  React.StrictMode adds deprecation warnings

• [ ] [Popper] Upgrade to popper.js to v2
  Nothing to deprecate

• [ExpansionPanel] Remove component
  deprecated in #21560

• [ ] [Button] Make primary the default color
  Change of default prop, can't be deprecated.

• [ ] [core] Type custom onChange implementations with a generic react event
  Don't know how we could achieve that with TypeScript

• [ExpansionPanel] Rename to Accordion
  deprecated in #21560

• [ ] [system] Introduce visuallyHidden style utility
  Not important

• [ ] [TablePagination] Add showFirstButton and showLastButton support
  Too much work

• [Collapse] Add orientation and horizontal support
  deprecated in #24079

• [ ] [Divider] Use border instead of background color
  We can't add a deprecation