But if GF got her license changed to say "M" instead of "F" and had her breasts removed--then her having a baby would be a travesty when now it is completely okay?

(Is it supposed to make me feel good that while you look down upon this couple, my family is okay--so long as we abide by the strict guidelines of GF using female pronouns and keeping her breasts? Want to tell me the details of how you had your children and I'll tell you if I approve of those methods?)
I don't see where this person is flip-flopping. He has not changed the M back to an F. He has not asked for people to start calling him a female again. He is not asking to reverse his breast removal surgery. He clearly feels like a man. But he also has a uterus and that uterus is very useful for producing babies, so he is making use of it. He is still legally a man--merely having a child does not imply that he wants to be a woman or that he legally is one.
You seem to be assuming that one can not identify as and feel like a man while also employing a uterus to have a baby. The majority of F-to-M trans men still have uteruses. They still have to deal with the usual female-reproductive issues in their bodies--they still have to go to the gynecologist and get a monthly pap smear. If something goes wrong--uterine cancer, ovarian cancer, etc they still need to have the exact same medical treatment as a non-trans woman does. They are perfectly capable of living as, identifying as, and feeling like a man despite this. Extrapolating from this typical experience of F-to-M trans men, I see absolutely no reason to think that one can't feel like and identify as a man while having a baby.