You’re correct, they don’t say anything specifically about plugins or studio. It could technically fall under bypassing the filter (this can be done with textlabels, so if it IS enforced it is a very stupid rule for this to be in studio.)
I’m just warning that I’ve seen it somewhere that you cannot replace Roblox’s chat filter with your own.
Unrelated rule, but I believe this still applies to plugins as it allows users to directly (and privately?) chat with eachother. (which again, stupid, cause textlabel)
Conspiracy territory, but I believe a huge part of the reason that team chat was removed was to prevent <13 users from using it. (again again, textlabel) Perhaps it wasn’t compatible with parental controls, or some other reason. It wouldn’t make any sense for them to remove it entirely just because it was bad.
That or it was just that bad and I’m overthinking it, but it would be in line with the changes they were making to prevent <13 users from chatting.