So people who want this feature to have better QoL are getting punished, because someone could be mean and harass others to turn it on?

It would be a toggle for a reason, with default being off. If someone is being mean and starts harassing others to turn it on, then they should be reported and get punished for their actions.
Saying that you don't want to allow chat bubbles in battle cause of potential toxic behaviour, is idk, like why even have chat at that point as well, just simplify it like in Crystalline Conflict