Nah, nothing new to see here. That warning is published by every studio any time there are sudden or flashing changes in light. It's a "protect our asses from lawsuits" thing that has been around for years. This is just getting attention because it's Star Wars. Epilepsy is a real thing and the industry knows that their movies can cause issues, so they all warn about it.
My son had epilepsy* and we only ever took him to one movie because the sudden flashes would set off seizures. In fact, we never watched TV in a dark room if he was in there with us. That Disney is warning is a good thing, but I don't think it says anything about the movie one way or the other.
All Star Wars movies are filled with bright flashing images in sequences ranging from a few seconds to several minutes (opening scenes in Episode III, anyone? Ugh, that took way too long to tell us nothing!
) So, yeah, I won't read anything into that beyond standard fare litigation protection.
*I don't like to bring this up, and only do so because I have a great deal of experience with the topic.