While I don't think another Summer Game Fest was OFFICALLY announced for 2021, this Tweet along with Geoff Keighley's responses in the replies indicates it will be back for 2021.
I personally hated the concept. It was good in theory but it was WAY to drawn out. My hope is that it is contained to only a week around typical E3 time. I know COVID really fucked with everything last year but last years Summer Game Fest made me REALLY miss E3.
So, Era, are you excited it's coming back? Do you want to see any changes done to the format?