Actually yes. By default, a software license lasts for as long as it's granted. Only open source licenses are perpetual and non-revocable by design. And if a store, any store, were to keep a game that the publisher can no longer distribute, then it would really be breaking the law.
Yes, the law is bad. (Copyright sucks if you ask me.) But to claim that itch.io somehow has a duty to... what... go against the entire legal system? Another famous organization tried just recently. They're called the Internet Archive. You know how that ended, right?