>>4475578
Sooner or later, all the girls will be interested in him because he is partly the focus of the game, in addition to the overall story with the ark, etc.
From a lore perspective, it wouldn't make sense for them not to be interested in the MC, who they are automatically attracted to. Graves and Cindy's relationship is more like that of a mother and daughter, which they make clear through their interactions. Similarly, Siren and Mori have the same kind of relationship.
As ships outside of the lore, it's nice, but on a narrative level, they don't really work,
Besides, Yuri isn't that popular in that context, and for other reasons, I don't think it would be well received in a game that doesn't have that focus. If there were a canonical Yuri couple, they would just end up like Mihara and Yuni, having threesomes with the commander, being bisexual.