So according to MisterMonopol's stream (He's just starting an H3 run btw), the current theory is that sword flying is gone because H2A is based on the Vista port which had some bugs fixed?
I don't think this is confirmed yet but it'd be pretty shitty if it's true. 343 has been talking a lot about how they've intentionally kept all the original bugs intact, so it'd be pretty lame if they turned around and fixed a bunch of them without letting anybody know...
It's not going to change unfortunately. I hope they change Envy though. That was completely unnecessary.