Seems as though the patch broke things, as someone here corroborates:
I really hope not. It looked like a nightmare to try and manage modding in that area, and/or impossible, last time I tried. And I feel PCK and BNK files are probably responsible for why some of my modded audio files weren’t successfully overriding game sounds, as noted in that other thread, which I was never able to fix.
I’m really not a fan of AoE2:DE audio modding compared to HD and before (not a secret). And the incessant battle alarm/horn sound is incredibly annoying still, both in terms of its sound profile and it’s frequency of occurrence. How it has remained intact for 25 years is beyond me. And how it is not 100% moddable is beyond me, too