Originally, the announcement was supposed to take place on June 3rd. Sadly, this will not be the case – The Beta Launch Show has been postponed indifinitely.
”We are excited to tell you more about Android 11, but now is not the time to celebrate. We are postponing the June 3rd event and beta release. We’ll be back with more on Android 11, soon.” – Android Developers on Twitter

Google did not the reasons behind its decision. We can only guess that it has something to do with coronavirus outbreak and the street riots.