It's obviously just a temporary thing for April fools. Just turn down crowd volume until they remove it again.
Unless this part was actually unintentional and a mistake, and the tweet about the crowd audio was actually legit. That's all very confusing when coupled with April fools. It's the 2nd now, it wouldn't kill them to make another tweet explaining what was the actual April fools and what, if anything, was not.
u/Psyonix_Ted? I've been a good boy and not tagged you for anything for a long time now. :p
Just turn down crowd volume until they remove it again.
One man audio ended at 9am PST this morning