MSQ

[wereotter]

The story of G'raha Tia was related to the main story, but the MSQ of shadowbringers can almost entirely stand on its own feet without any real understanding of the relation of the Exarch to the crystal tower on the source. The post-Shadowbringers MSQ is a slightly different matter, but even that could be explained away with a few lines of expositional dialogue, instead of wasting hours of each player's time going through the crystal tower raids.

The tower basically serves as a mcguffin that links the source to the first, but it's not integral to the actual storyline, except as far as it was shoehorned in.

To be fair, they do that a lot... I hadn't thought about what happened with the story of the tower until this expansion and had forgotten who Graha even was.... but since this is story that leads directly into other main scenario quests, they decided it was mandatory