Actually, Google had postponed the release of the first betas of Android 11 to 'later'. Then Google probably made a mistake and unintentionally released a beta of Android 11 for pixel devices.
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On Twitter there is this entry where people list the new features they found.
This is the new "power menu" settings in Android 11. This will control the cards & passes and Controls feature that I tweeted about earlier today. pic.twitter.com/EdHNpXmwiR
— Mishaal Rahman (@MishaalRahman) June 1, 2020
New submenu for enabling Bubble notifications. Settings > Apps & Notifications > Notifications > Bubbles. pic.twitter.com/R1cla9oPMm
— Mishaal Rahman (@MishaalRahman) June 1, 2020
Here is a short overview about this topic.
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