The rampant ones that were probably the majority that most people regularly hit: seem to be fixed or at least helped a lot.
I could 100% repro locking out my characters (load crash) by going into Silent Halls in Blackwood--I'd crash loading into the area and then couldn't recover the character unless I logged in on an older pre-Series console. Trying that out with bated breath today, I enter/exited 5/5 times without crashes, which was a very welcomed change.
Haven't tried BGs or other things that were crashing every 3-5 minutes yet, but now I'm optimistic given that was an instant, guaranteed crash.
Likewise -- I played for 5-6 hours yesterday and didn't crash even once (Series X) despite a lot of being in Blackwood and even (gulp) Silent Halls. I was averaging closer to 5-6 per *hour* before the maintenance patch (double that if I didn't avoid PvP or other player-dense areas) so there's at least a big change to one category of crash.
It seems like there are still some other crashes (the champion point UI one is particularly concerning) and it's unfortunate that some people are hitting those quite a bit (I'm thus far in the lucky camp of not being as impacted) but this still seems like a significant "win" for stability.