If you don’t access Microsoft Teams data via Microsoft Graph API, you have nothing to worry about and this is not for you. If you do, Microsoft just announced two breaking changes.
For a long time, Microsoft have been running a Beta API endpoint and a v1.0 API endpoint for Graph for Microsoft Teams. I’ve talked about it before on the blog in the context of Microsoft Teams PowerShell.
In the last week of September Microsoft will remove the following beta APIs,
- /teams/id/apps — use /teams/{id}/installedApps instead.
- /teams/id/channels/{id}/chatThreads — use /teams/{id}/channels/{id}/messages instead.
- /groups/id/channels — use /teams/{id}/channels instead. (the team ID is the same as the group ID)
The same functionality is already available through different APIs. v1.0 APIs are not affected. Reference here
Microsoft are also adding/renaming new API’s
- /communications/calls
- /communications/onlinemeetings
- /user/onlinemeetings – This will support creating online meetings with both user token and app token.
The previous APIs, /app/calls and /app/onlinemeetings are still supported in beta for backward compatibility.
There are also some changes to types and enums, details here
Reference:
Breaking change: redundant beta APIs for Microsoft Teams to be removed
Breaking changes: Calls and online meetings API updates in Microsoft Graph beta

Great heads up, just a question, when should we expect most of these beta features be released in a stable branch? Say in a minor or major release? We are eager to use some of these in production but are slightly worried.
Thanks again!
–Sam