As long as the FFXIV devs don't endorse addons, addons won't become a rampant problem. They already nuked Paisley Park's functionality and I bet they would do it again once they see people openly streaming with non-ACT/Reshade addons. Moreover, they will probably have to do investigations first and find out ways to combat it server side like they did with PP.

In a way, I'm kind of grateful that people are streaming with stupid shit like Sonar because it's been an issue for years but people kept super quiet about it so SE couldn't do anything. Now that it's out in the open for everyone and God to see, no doubt they will have their evidence and big reason to kill those things.