Asura facial animation issues

I wasn't sure where to post this - it's a bug? An update? A feature? - but ever since the last patch, several Asura face presets have some odd distortions around the mouth during most emotes and animations. Rather than moving naturally, the corners of the mouth are drawn down way further than they ever were. It's bizarre, distorted and frankly offputting after years of seeing one thing and now getting another.

Any word on what's caused this and whether or not this will be reverted?

(EDIT: Saw it's been put up on the Bug Report forum. Apologies for this extra post.)