Actually, it has become so. Around 80% of MtF transexuals not only have not transitioned, but do not intend to. The current political movement by trans activists is to separate sexual identity from sexual characteristics entirely. Yes, people have unironically declared that they have a "girl's penis." What is more, many of these trans activists are HIGHLY aggressive to those they term "TERFS" which theoretically stands for Trans-exclusionary Radical Feminists" but essentially is used for any woman who refuses to treat a man as a women (including not wanting such men in our bathrooms, changing rooms or representing us as women's counsellors like the 19-year old boy who got a Labour woman's counsellor kicked out and replaced by himself because he felt there needed to be more representation for "trans women"). I know some Lesbian women who have been harassed by men who call them bigots for not wanting to sleep with them on the basis of their genitalia.
TLDR; your terms are out of date. Most MtF "transexuals" are in fact transvestites only and the term has deliberately been confused in accord with the desired outcome that sexual characteristics should no longer be allowed to determine if one is a man or a woman.
I disagree. I am very against one's sex determining what one can and cannot do in society as is pretty much everyone I associate with. Yet myself and many others who are against these things are also concerned about trans-activism and it's political influence. What I do come across is people who haven't had personal experience of trans-activism (and I'm going to class you in with this group, Vonhelmet unless you claim otherwise) and naively assume it's distinct from transvestism and that it's defensive rather than aggressive.
Here's a small sampling of the abuse women who don't accept cross-dressing men as women get, routinely.
https://terfisaslur.com/
(n.b. contents of the page is an ongoing catalogue of the abuse. Can't promise adult language wont appear on there. If it needs to be remove, it's easily found on a search yourself using the prhase "Terf is a slur". Hopefully it can stay though as it's a serious matter.)
Please note two things: One, the majority of these are from men who have no intention of transitioning but have decided they are women and are directing their considerable aggression against women who don't accept them. Two, recurring instances of MtF trans declaring that their penis is a "girl dick", "my penis doesn't undo the fact that I'm a woman" and "impregnating someone doesn't make you less of a woman."
I can tell you that I feel a great deal less safe going into a bathroom or a changing room and seeing someone who is (a) a guy, (b) straight, (c) thinks they're a woman. Which is now happening.