They are telling EVERYONE in my mailbox just a few minutes ago (as the O365 admin)

"Select Microsoft 365 and Office 365 subscriptions that include Power Apps and Power Automate are expanding with the introduction of Microsoft Dataflex – a built-in, flexible datastore supporting relational, image and file data with a one-click experience for deploying solutions natively in Teams.
Your users will be able to access these public preview features in Teams beginning in mid-August.

  • With Dataflex, Power Apps will provide an integrated app studio that lets users build and deploy custom apps within Teams."