In my opinion this question doesn't have a general answer. Different casinos have their rules regulations and privacy policies as well as terms and conditions. Therefore to be able to accurately tell what would happen to the casino account, you would have to go through the terms and conditions policy of that casino. However for most casinos the account would either be deactivated or frozen especially if it contains some funds. Most times after a proof of ownership the casino account can also be retrieved back to the owner.
Most of the time trying to retrieve such accounts can be very tasky especially if it has some funds in it. Therefore you should try to login to your account at intervals to prevent any suspensions except you don't wish to make use of it anymore.
The most important thing is for gamblers to never leave any funds in a casino account they may not use for a long time, as in this way even if the casino in question was very strict on the application of their norms and the account was deactivated or even deleted, it will not matter at all, since you could always create a new account and begin to gamble at that casino once again, and you could do so without violating any rules on their TOS, since most casinos require only one account per client and that new account will be your only account anyway.
