Taliyah was initially conceived of as transgender by her DNA team.
Which gave me a thought...
This might sound odd, but I wonder if Taliyah was put in the same situation as Remilia IRL. Noxus might have had mages or straightup surgeons who would be able to do the reassignment. So they promised her power, they promised they'd let her be who she wanted to be. And then they may or may not have botched the procedure, and dumped her when she didn't agree with their ideals.
(Compare: Remilia got roped into playing for Renegades despite being psychologically a mess because Badawi promised her surgery. Surgery ended up being shit and left her in permanent pain, and Badawi screwed her over in other ways too.)