Following #13541, we've addressed some issues and defined how the new feature must improve:

Bugs

• Data to create discussions on direct messages is incomplete (Regression: Discussions - Invite users and DM #13646)
• Cannot select more users to invite on "Create a new discussion" modal (Regression: Discussions - Invite users and DM #13646)

Open for discussion

• Mentioning discussions?
• Nested discussions?
• Slash commands for discussion creation/handling?

Improvements

• Join without send a message
• Limit size of name field
• Promote/convert discussions to channels/groups
• Rephrase "has joined the channel" as "has joined the conversation"
• Improve attachment for quoting discussions
• Show discussions as section option on popover