This is exactly right! To be sure, I queried our developers to see if the mask was supposed to have modulation, and they confirmed that it was not designed to modify the voice.
What I dislike about this is that you seem to suggest that it would have ever been a possibility for the Development team. They can scarcely draw out content, and you're checking up with them to see if they modified every piece of existing voice acting script for the sake of a single cosmetic piece.
I hope that trip was part of your coffee run or toilet break, or something.