There was a tweet going around from someone a few days ago stating that multiple studios approached Epic about remastering Unreal back in 2017, and the response they all got was that they had no interest in re-releasing old games because nobody wants to play them.
Considering the overall reception for the remasters, the Halo Master Chief Collection, etc, that tweet has aged like expired milk in the desert sun. Epic just wants to sell their new engine everywhere and went out of their way to kill their old IP's, and throw more crap into Fortnight. Unless they see enough $$$ from what Nightdive is doing I doubt they'll want to do it. From their perspective I imagine they see the Q1 and Q2 remasters as just a marketing hype push for a future Quake game, since we're talking the narrow-mindedness of corporate suits here. Hopefully I'll be proven wrong and they'll decide the old UT needs some love, but I'm not going to hold my breath for that to change any time soon.