I think what needs to be considered is, if you have a mic or not, to play Identity. Not consider TTS, so that players without a mic, can play Identity.
The focus should be to talk over a mic. If you want to contact someone across the map, message or call x person on your phone or a payphone.
I can imagine TTS being abused and be very absurd when trying to have a proper conversation. As well, as the time it takes for someone to text something out, compared to just talking over your mic.
A microphone is absolutely necessary, to be playing Identity.