What prevents Activision and Microsoft from re-releasing Heretic 2 now?

I’ve known for a while that the dispute between Activision and Id over the rights to Heretic 2 prevented a playable release of the game on modern systems, but now that Microsoft’s (and therefore Bethesda+Id’s) acquisition of Activision has been completed, what prevents the release of a playable version on Steam and modern consoles today?

Heretic II is a great and beautiful game, not only it continues one of my favorite sagas of all time, but it is also a title that, if we consider its year of release (1998), stands out as being really ahead of its time: just compare it to Tomb Raider 2/3 to see how pioneering it was in some respects, such as the controls, freedom of movement, polygonal modeling, and animations. The graphics are still absolutely remarkable today, and the gameplay is still fresh, thanks to the ability to choose between using the WASD/mouse layout or just the keyboard controls (something not possible with the previously mentioned TR2). The story is still enjoyable overall, a good conclusion for the saga, awaiting a hypothetical third Hexen.

Of course, it would be a dream to have a remaster of the same quality as Quake 2, whose engine is used on Heretic 2, but even a patched version of the game would be acceptable. In the meantime, I continue to play Heretic 2 in the only way currently possible, which is on a Windows 98 system.