A little more transparency from MSM would be nice as I don't think everything is quite correct what they have stated.
But from the boxer's perspective, I'd say it's fine as long as She/He/It is not a fully biological man.
If I understand it correctly, she was born a woman, but has some disorder with chromosomes. If she is biologically a woman or intersex, I think it would be fine for Her to compete, but if She is a biological man, it would be wrong to compete in the womens category