While you're kinda right, Cyella and Unukalhai are sadly kinda like Gaia at the end of Shadowbringers.

There's no reason on Etheirys why Gaia wouldn't be with Ryne when the Scions leave the First. Whatever you wanna call their relationship, there's no way Gaia would leave her alone at such a hard time... but she's side optional content. Someone who hasn't touched Eden would be like... "Who?" and it's pretty much the same for Unukalhai and Cyella.

Solution: Make their quests MSQ mandatory and implement them in the Saving the Thirteenth arc now. There's so much fluff in ARR that making such characters as Unukalhai and Cyella optional and even Gaia (if you ask me) is kinda criminal.
Remember when we went on a wild goose chase with Illberd to Eastern Thanalan to find some stolen crap or whatever? Me neither. But that's a forced part of the story.

They made Crystal Tower mandatory, so here's hoping.
Feel free to disagree.