@androp - Yes, they have stated on Discord and in the Chessup community forums that the phone app will still be available and in some instances, necessary. Here is the quote from the Discord channel:
<@709821110132146296> Hi there! Yes, WiFi for connecting to Chess . com and Lichess to play games. If a user wishes to analyze their games for post game analysis, run a firmware update, etc they will need to use the ChessUp app. The app will never go away, all the same features will still be there!
I honestly don't know but someone will reply who does.
Frankly, I got this mainly because I would never want to have to use a phone for it to work with online play.