Ketlen Vieira is the most logical contender at Bantamweight, but you sure as fuck can't headline with that, so they'll have to get her one match and maybe commit to a marketing push (10-0 with two fairly big names on her resume and only 27, I have no idea why they aren't trying to market her more, there's no downside to marketing someone who's highly credible unless they're outright annoying). The winner of Holm vs. Aspen Ladd is more likely and I guess I'd be okay with that one.
Featherweight is sort of fucked right now though (now and always). Megan Anderson vs. Cris Cyborg could be used to headline a Brazilian card. If Megan pulled off the upset, she could be given a shot at Nunes' belt, and the division could be given a stay of execution. If not, then the UFC could just let Cyborg go into boxing and cut Megan. I'm not saying I want this, but it would be a natural and logical end to the division from the point of view of a company unwilling to invest in it. It would get them one more second-tier headliner and would also let the illusion of a division survive long enough to sufficiently milk Nunes' Champ Champ gimmick.
While obviously it's slim picking out there, I feel like the UFC didn't even try to make a W145 division. I get that half of y'all are hardly fans of WMMA, but it seems silly to open a divisions when you aren't gonna put the bare minimum effort into ensuring its survival if things don't go absolutely perfect. The TUF season was 1) a gimmick with few actual Featherweights (possibly zero) and 2) a good way to sign some natural Bantamweights who aren't gonna drop down to Flyweight. Aside from that they've only signed Cyborg and Megan Anderson, and with Cyborg they had no choice. They could have made this work, had a micro-division with a natural progression to the title that could have been done without painting themselves into a corner, but considering the UFC can barely manage to get their shit together at Welterweight these days, W145 never stood a chance.