IMHO: the bottom line is that many IP owners wish to retain full control of their properties.
Re-releases & re-masters may often compete with earlier releases. However, if the IP owner is able to remove access to the earlier releases, THAT competition dissolves.
Given that studios & publishers are seemingly lacking in "new" creative effort or ideas, simply putting a "fresh coat of paint" on prior releases is becoming more popular.
Besides, if the "license" to use/play a title expired or was revoked, ANY actual use of it would be illegal and open to litigation - surely in the favor of the IP owner.