Honestly, I didn't expect that Epic would be okay with this.
It's nice to see, and bluntly, after a game has gone through all the different stages of buying and owning, why not make it free? Makes it that much easier for nostalgia nerds to have awesome LAN parties.
I don't think this makes up for the long list of consumer hostile things that Epic has done, but it doesn't hurt.
The next thing I'd like to see is to have games open sourced when stuff like this happens and the game is well into obsolescence. At least someone can pick up the mantle that studios don't want to have anything to do with, when it comes to making the game compatible with newer operating systems, or alternative operating systems (like Linux, though I think UT supported Linux), or so that it can be built for new architectures like Apple's new arm based silicon.
There's no profit in the game anymore, so just let people have it so they can fix what you don't care about anymore.