In Switzerland Sunrise offers a plan with free traffic for WhatsApp. This means Deaf people can send each other Signed Language videos without limits by WhatsApp.

I work for a non profit developing video communication solutions tailored to the specific needs of the Signed Language communities. For example, audio is not necessary, perhaps even detrimental because Deaf people don't realise problems with audio like feedback or embarassing noises during a call. Or degradation on bad connectivity. This is subtle. Signed Language communication needs a constant framerate to prevent jerkiness of the expressions. Just reduce image quality instead! Ugly block artifacts don't impede understandability.

In other words: ISPs zero rating WhatsApp is blatant discrimination of Signed Language communities. This also concerns phone relays and other services.