TL;DR: Meta-attraction is a lie. If you're straight after transitioning you were gay before, but in denial. You just saw women as a proxy for your attraction to men.
As follows my reasoning:
In Blanchardism, there are two distinct types of MtF transsexuals: AGPs and HSTS. AGPs are sexually and emotionally attracted to the idea of being a woman. HSTS are strictly homosexual even before transition and remain so. But what about repressed homosexuals who become transsexuals?
The power of the human brain, to trick itself into believing 'propaganda' is truly remarkable. So why should it not create paraphilia to feign an attraction to women, where instead of being attracted to the woman, which repressed homosexuals are not, they divert their attraction to the idea of being a woman (thus being able to be attracted to men). They 'use' the women as a proxy for being attracted to men
As autogynephilics commonly present later in life, the idea of being attracted to women may already be so deeply engrained in their belief systems, that they confuse their artificially (self-)created gynephilia for real attraction to women.
Now because there definitely are purely fetishistic transitioners, a further distinction needs to be made: If the initially gynephilic transsexual remains attracted to women in some sort even well into their transition, there is evident reason to label them as a purely fetishistic / true AGP.
However, if the transitioner becomes 'meta-attracted', i.e. purely androphilic during the course of their transition, there is no fundamental difference between her and an HSTS' attraction profile. They become a pseudogynephilic homosexual transsexual.