It depends entirely on the jurisdiction. Some places like New York City, Toronto, Seattle etc have specific topfreedom statutes. This allows men and women alike to remove their tops in public. Other areas have more antiquated laws that allow for the double standard.
There are no laws against complete nudity on federal lands actually like National Forests etc unless specific parks have specific guidelines. This is why nude beaches are often on protected National Seashores. State or local law enforcement does not have jurisdiction over those matters there. Then there are actual government authorized nude beaches (We have two in Oregon on state-owned lands ) where the possibility of nudity is posted.
Private property use laws usually, but not always, protect you in places like yards etc. even if this space is casually viewable by the public.
In areas where public toplessness is illegal, a trans woman could easily test that law and I'm guessing it would come down to what your gender legal status is, as to whether you could be cited.
Social media sites like Instagram, Facebook and others have struggled with topfreedom as well, whether it be pictures of mothers nursing or other, artful nudity vs. other forms etc. There have been trans women that have tested these during their transition. In other words, ok Instagram when do my breasts become offensive? The result has been loosening of terms and conditions around nudity and there are a lot of Instagram users like "the naked traveler" that have been the result.