You're connecting to the database, it can be basically anywhere on the server, so yes it "allow it".
Example:
- lets say we have two subscriptions, XX and XY
- if you use your database for domain in subscription XX and you have need to move the same domain in subscription XY you don't really need to move the same database in subscription XY
- this will work, without any problems, however, you will want to move sooner or later your database in subscription XY for obvious reasons (you shouldn't have circus on your server, you want order and that means every subscription with it's domains/databases and then when you want to delete subscription for some reason, you won't have to worry about having database in other place)
As Faris explain you, you need to put that domain as new subscription and select new IP for it.