Reading way too much into it. All the LIs are bisexual regardless of their gender or the Crown's gender. The LIs switch randomly between genders for bisexual Crowns just because I figured that would keep things interesting.
Also, an important point I want to make: the LIs do not have "canon" genders. I always intended them to have both male and female versions. The reason those versions are in the artwork is because those are the ones I just happened to commission first. Playing with Xelef is just as canon as playing with Xelara, etc.