Quote Originally Posted by Krotoan View Post
It was suggested by the lead writer that they be completed "To understand the story"... I don't think they specifically stated it'd be necessary to participate.
It didn't use to be required for quite some time, after digging around the Lodestone for past updates I managed to find this again. https://eu.finalfantasyxiv.com/lodes...7a304e8584f88a


Also, while there is nothing stopping them from making more things requiring to be done for the MSQ, they won't do it without good reason. The Crystal Tower raids story is pretty essential setup for the story of Shadowbringers, and the story pretty much directly assumes that you have done those raids and the quests around them.