I'd love some more KOTOR 2 characters. But I hardly think the new characters all suck. I didn't love all the Anniversary Era characters, but I was pretty excited about Stormtrooper Luke and the new Darth Vader (I'm an OT kind of guy). And since Andor was, in my opinion, some of the best Star Wars ever made, I'm really happy about getting these Andor characters. Plus we just got Satele Shan, who is a KOTOR-related fan favorite—even you can appreciate that one, right? So on the whole, I think the new characters have been pretty good.
Still, you're right that more KOTOR 2 characters would be nice. There are a lot of potential synergies with existing factions and characters.
Speaking of, HK-47 and Visas Marr need Old Republic tags. HK wasn't just Darth Revan's assassin droid; he was also a companion of Jedi Knight Revan and the other Old Republic character we already have. And assuming that some future KOTOR 2 characters also get Old Republic tags, Visas ought to have some synergy with them.