Hello. I suffer from Spinal Muscular Atrophy and have been using the Move Pad available in the accessibilty options to position my characters while playing since 2019.
Now I know that this patch added a “Press and Hold Movement” functionality, so I have to stress that I have this option TURNED OFF and my Move Pad should work the same way as it did before the patch.
The way it worked previously is that you click the direction you want to move in and only a single mouse button is required to activate it and a second click (rather than “letting go” of the button) de-activates it. Every direction chosen is an auto-run basically. For example I could click on “Run Forward” and my character was still running (until I cancelled it with a second click) as I was clicking on the “Rotate” button or “Run Left”. This was very useful for content like battlegrounds or delves or when flying as it allowed my characters to keep moving while turning around or to run diagonally not just in one direction.
Since the patch this functionality only works if ONLY ONE BUTTON ON THE MOVE PAD IS PRESSED. PRESSING A DIFFERENT BUTTON CANCELS THE EFFECTS OF THE PREVIOUSLY PRESSED BUTTON! After the patch two buttons on the Move Pad can’t be active at the same time!
For example if I run forward and want to rotate my character to adjust the direction my character runs to, my character immediately stands still and starts rotating. If I press “Run Forward” and then “Run Left” the “Run Forward” bit gets cancelled and my character runs sideways, prior to the patch he’d have run diagonally in both directions at the same time.
Now as a disabled person I have to press “Run Forward” on the Move Pad and “A” or “D” on a regular keyboard to move and turn, which is extremely difficult for me, since I need to use both my hands to do it. I’m trying the “Click to Move” option which is slightly better, but it requires right-clicking, prior to this patch I could move in any specific direction with a series of left clicks.
This means that since the patch began I’m extremely slow to press my spells and abilities unless I ask a different family member to press “W”, “A”, or “D” when I tell them to. And obviously those people have lives of their own and can’t just sit down with me whenever I want to play.
I tried turning the “Press and Hold Movement” option on and back off again to see if that fixes it, it didn’t, I reloaded my UI, and I even tried installing the old “Move Pad Plus” add-on, but this patch broke it, too.
I’m frankly panicking because I saw no mentions of this on reddit, the WOW forums, or wowhead and I fear this change may get lost in the shuffle amid all the Legion Remix bug reports, but it completely breaks the game for me.
If this change is intentional (which I doubt cause no disabled person would advocate for this), then I ask Blizzard to introduce an option for the Move Pad to behave as it did previously. If it’s a bug then I hope it gets fixed faster than the Auto Loot bug.
I’m sorry for having been born disabled and I’m sorry for being alive. It’s depressing to have fewer and fewer games to play as the years go by and my illness progresses. WoW is one of the few options I have left. But I can’t imagine playing Midnight if this doesn’t get fixed. Now (without help) I’m too slow to play the content I most enjoy (battlegrounds and delves) and am stuck doing world quests. 
P. S. I didn’t know if I should post this on “Technical Support” or “Customer Support”, decided on the former.