This field needs to be checked everywhere the account is used.

Usually something like this would be enforced once in a centralized location (in the data layer / domain model), rather than at every call site.

for the automatic removal after x amount of days

This gets tricky because in many jurisdictions, you need to ensure that you don't just delete the user, but also any data associated with the user (data they created, data collected about them, data provided by third-parties, etc). The fan-out logic can get pretty complex :)