SharePoint Roadmap Pitstop March 2021 (microsoft.com)
Planner’s New Roster Containers
This release of a new type of container in Planner will allow plans to be created independent of an M365 group. This will be enabled by Roster containers, which is a simple list of members stored in Planner that can contain any user with a valid AAD ID in that tenant. We are calling plans contained by Rosters « Roster plans ».
What’s New in Microsoft Teams | February and March 2021 Updates
Introducing PowerPoint Live in Microsoft Teams – Microsoft Tech Community
Important updates to Guest Access defaults in Teams starting in February 2021 (microsoft.com)