Yes, the AI for thralls now doesn’t teleport to you anymore. So when they do get stuck, you have to backtrack to them, use the move and guard function and place them somewhere on terrain, then order them to “Follow” you again, otherwise they will not move.
The return command only has them forget the previous “move to” order, and no longer works as prior to the point where the thralls decided to take overland routes and cheat their way to you. Now they don’t, because I assume they were bogging down the game to where it was unplayable. I would rather be able to play the game than have runaway AI code, so I’m okay with this.
You have to be very careful now when taking thralls outside, they are very prone to situations where they get stuck in terrain, can no longer zip to you, and get gibbed. If you have to run away, an NPC camp will chase your thrall until they kill it, sometimes crossing zones.
If you are running alone, they give up and return to their previous spots - this applies mainly to archers, they give up easily when you creep up on them. You take a few steps back and they will reset. But if you have your thrall out, be ready to run to the ends of the map. They will never give up trying to kill you or the thrall.
This is why… Having them get stuck in terrain is such a big issue. Also them not being able to swim in water is a problem. Because they can’t follow you until you get to the other side.
I haven’t played with a horse + companion yet. But it should be even better now. 
Seriously though, I have noticed attempts at making the AI more responsive and better alert to reacting to your presence and overall I feel path finding has really improved, but the “stuck thrall” has nothing to do with path finding, it’s just a glitch that occurs once in a while that ruins the whole experience.
Also, NPCs and thralls equipped with a shield, sometimes just hold the shield out and stop. And…that’s it. They just stand there with their shield out, waiting for something to hit their shield. Until it does, they don’t…do…anything…else. There is a glitch where they get stuck in “block” stance, they are not actually reacting to anything anymore.
The “shield block” stuck is the other variant of the stuck thrall issue, which is not as severe. They eventually recover from it. But the serious one is the one where the thrall does not move anymore and stops responding until you directly micro manage the situation (even if you can’t because there is combat).
It’s really hard to have an AI follow a player around, since a player does not move like an AI and is not hindered by rules or terrain. It’s quite a challenge. Especially since in CE, a player can climb and swim. I think you guys have made great strides to improve it but it’s still a formidable hill to climb.