I think if people literally turn off sports where females are unfairly pitted against males then sponsors might start reacting.
I think it would be worse than that - fewer watch women's sports anyway, if males started taking part women would stop watching as well, and it could all peter out.
MtF have an advantage because of bigger bones, lung capacity, higher testosterone levels. FtM have an advantage because they're taking testosterone. Natal women are at the bottom of the heap.