Miricles I agree that transvestites have largely disappeared, and now go down the trans route.. I don't think it's very fashionable to admit to getting a kick out of cross-dressing, but it's very 'in', and absolutely protected, to instead identify as trans.
There are several problems with your suggestion that our 'support' needs are in fact a need for education/re-education. (I think most of us are reluctantly extremely well-informed about gender issues, by necessity...)
Seeing the solution for unhappy partners as education is judgemental, and ideology-based, and not really about 'support' at all. The only organisations offering 'support' to partners primarily work to support trans people, so they have a very clear ideology and I would argue are poorly-placed to ethically offer non-judgemental, neutral 'support' (just like the abortion 'counselling' being offered by LIFE and SPUC).
Unhappy partners regularly report that these organisations offer, after an acknowledgement of the trauma and loss involved, re-education and encouragement of acceptance. People are counselled that they are in denial of a factual truth about their partner's gender and find the experience negates their experience and personal history. They are likely to be encouraged not to 'misgender' their partner, when decent counselling should support someone's lived experience.
I for that reason had generic counselling which was NOT about politicized re-education, correcting my thinking, and did not seek to keep my marriage intact. I was allowed to talk about my ex as 'he' and as a man, and was validated and accepted as not believing that he is really a woman. Ethical relationship counselling does not set out to keep a couple together, but for some reason where one party is trans, this seems to be an acceptable aim... sadly the familiar story of different standards applying where someone is trans.