I’m switching the status to Partially Done.
The request for a Preview Team is still in the works. No new information is available at this time.
Team Discoverability is still being worked upon, no details are available at this time. If you support this idea please navigate over to the main topic and vote for it! https://microsoftteams.uservoice.com/forums/555103/
Change Prompt: this has been completed
Group Calendar is a priority for the team, and the feature team is continuing work on it. You’ll start to see some incremental improvements. We look forward to sharing more details and timeframes soon.
Adding any emoji as a reaction remains under review.
I am marking this as partially done to let you know a new reactions bar with Like, Heart, Laugh, Surprised, Sad, and Angry has begun rolling out to all users.
The engineering team is continuing to work on adding support for multiple accounts on desktop clients. We will first launch support for 1 work/school account and 1 personal account so users can enjoy Teams for work and personal side-by-side. Windows and MacOS. Support for multiple work accounts is still being worked on and will come at a later date.
You can track status via the roadmap here: https://www.microsoft.com/microsoft-365/roadmap?searchterms=68845.