And about downgrading. FIDE Master (the generic open title for both men and women) and Women’s Grand Master (women only) have the same rating requirement (2300). But the WGM title requires three tournament norms as well (where you play at above rating over 27 games in total against a high-enough rated opposition), whereas FM is based purely on rating. So WGM is considered more prestigious than FM and correspondingly there are far fewer female FMs than you would think in a normal title distribution, because female players good enough to be a FM invariably go for the slightly tougher WGM title that comes with potentially a few more perks in terms of free tournament entrance fees and whatnot.
I expect former WGM would therefore be downgraded to FM. Women’s International Master to Candidate Master (again same relationship of identical rating , but no norms required for CM). Women’s FIDE Masters and WCMs would be shit out of luck dropped altogether because they are below any comparable open title.
The hierarchy of FIDE title goes Grandmaster (minimum rating of 2500 elo + norms, any gender) > International Master (2400 +norms, any gender) > WGM (2300 elo + norms, women only) > FM (2300 elo, any gender) > WIM (2200 elo + norms, women only) > CM (2200 elo, any gender) > WFM (2100 elo) > WCM (2000 elo). Also certain tournament wins can substitute for norms. So if you were a female International Master (and there are a fair number of those) and transition to male it would make no difference - it’s already an open title. But if you’re a WIM, as above I assume you’ll get downgraded to the lesser open title of CM.
That’s how I assume it will work.