Anyway,WHAT APP IS IT? what is this GENERAL EMAIL? Should we ignore it?
Yes, I do think it is a general email
You should not ignore, as there is apparently a risk after jan 31 not to be able to resubmit.
Unfortunately, they don't tell which app.
To know which app, you have to go in appStoreConnect and select each app. If you need to update, you'll get a specific warning. See details here: https://developer.apple.com/forums/thread/809243?answerId=869488022#869488022
If so, you should update by resubmitting with the age information fully completed.
Topic:
App Store Distribution & Marketing
SubTopic:
General