And certain features that don't disrupt anyone else's game and or experience can allow people to understand and be in control of what's happening. The thing is, that there are systems that exist that let players with disabilities be on par with everyone else. Other games use them, and not using them is just turning people away from the game that doesn't have those features and onto a game that does. It's not like FFXIV raids are hard, you can afk or auto attack or heal yourself and not participate and still get by fine. No one can tell if you aren't participating much at all in the first place let alone call you out for it and have any evidence to support it. There is harder end game content and 5 man parties that people who have disabilities would struggle doing. If such things easily exist to let everyone participate in the fun, why not have it implemented?
timers and mechanic announcing honestly just prevents constant wiping more than anything. I've been in groups that have taken hours because we wiped constantly on multiple boss fights. Even when you understand the mechanics you can still slip up and having something to let you know whats coming can help, if you really don't need something like that, then don't use it. But there are people that benefit from that sort of thing for many reasons. It also doesn't affect you. You can get by in this game without knowing all that much about your job or boss fights anyway, it would be nothing but an improvement to save people's time and help people who can't go as fast as everyone else. The fact that there are rights for people with disabilities justifies giving features in games to help them play on par with everyone else. The fact that those features so easily already exist justify the reasoning to just add them to the game.