The check-ins are to serve as a daily reminder that you are being watched and your donations are still expected as well as your meeting attendance when stay-at-home is lifted. You better be keeping up on your studies and preparing for meetings as well as if nothing has changed.
WTBTS know well that with the taste of freedom and the bliss that comes from not going to meetings/FS they're going to lose a bunch of publishers when all is said and done.
They're trying to flatten their own curve with a daily nagging reminder.