From pausing the Battle League due to cheaters, false violation strikes, and Wayfarer rating issues, the biggest threat to many players is the move away from 32-bit Android devices. A lot of the good work by Niantic being undone is highlighted here.
Loosing 32bit means loosing players like my 2 10yr olds, who love to play pogo with me on old devices. Niantic obviously thinks every player has the latest ios or samsung phone. To get 2 new entry level 64 bit phones for them just to play pogo on is in the $800- $1000 AUD ballpark........not happening.