This is obviously SAF territory, so all I can provide insight into what I've read on discord (which I may have misinterpreted or misremembered). I know that SAF still wants to finish propagating asymmetrical tights to huge bodies, but wants to tackle some more specialty pieces that they've been wanting to do for a long time next issue. I also know that SAF is interested in doing a substantial revamp of heads that would include the integration of the earrings and domino masks that were teased a long time ago. I suspect that there would be numerous new head options including hair as part of that, but I suspect SAF would likely want to wrap up some of the other projects before tackling that.
I also know that there are few other art devs that have made substantial contributions to Rebirth, so it may be that one of them will tackle this even before SAF is ready to shift focus. All of which is to say, I think there's already a fairly long queue of desired costumes that are being worked through but who knows!