I haven’t seen any public confirmation from Zwift, but there was a lot of feedback about the constant “ping” from Ride Ons in this thread:
It feels as though they may have removed that problem and caused others.
Since the “ping” of Ride Ons was reduced, I’ve noticed I can’t say “Ride On!” or “I’m toast!” when riding in a large group. It’s almost as if one sound gets stopped as soon as another starts, so instead of hearing both the “voice” sound and a Ride on “ping”, the voice sound gets cancelled by someone else giving a Ride On.
If you were doing a workout and there were lots of riders around you when you couldn’t hear the workout noises, that would support my theory, but it is just a theory.