VoIP traffic is UDP, and will always be very easy to identify. We barely have functional circumvention strategies for higher-latency traffic types, so building a circumvention strategy for traffic like realtime voice with ultra low-latency requirements is a tall order. Honestly getting VoIP to work well in the best possible network scenarios is enough of a challenge.

I assume that higher latency communication like WhatsApp's push-to-talk "voice notes" works just fine in SA though.

I can't speak for SA but a lot of folks in Oman would message each other voice messages as a compromise.

Yeah, if they push back too much the Saudis would most likely just outright ban the entire service.