People always talk about MtF but never FtM. I imagine women would have an even bigger flipout over transmales entering women's shelters or restrooms despite having been born female.
Dunno it never bothered me to share a bathroom. We have a gender neutral bathroom at my job, so many of times I'd be dropping a duece and a female co-worker would come into to use the bathroom (RIP God rest her soul), and never had an issue other than offended nostrils.
The issue does seem to be women's bathrooms and women's shelters though. There was a story not to long ago about man and his children who was being physically/mentally abused by the wife/mother. He grabbed his kids and took them to a battered women's shelter because he had nowhere else to go, and they refused him.
Perhaps something to keep an eye on, maybe nothing.