This issue lists changes that should be made to Button v9 to better align its API and behavior with other v9 input controls.

Note: this list of changes is based on the current code for the control in master at the time this ticket was written. There are several PRs open for different controls so some items may be complete already.

• Explicitly mark the root slot NonNullable
  • In Button components: Making root a non-nullable slot #22147
• Remove the block prop
  • In Remove deprecated block prop from Button components #22149
• Add static classNames per Add static class names to all slots #21847
  • Mark the task done in the linked issue
  • In Button: Exporting class names of individual slots #20977