What am I reading? You don't just start growing glands ffs.
Your understanding and "theory" is totally, 100%, bafflingly wrong. The Telegraph is wrong too. This is not about a trans debate but a totally basic scientific fact.
All humans including males already have the anatomy (nipples, mammary glands, and pituitary glands) necessary to lactate.
It's the hormones they don't have, though in some cases males start naturally lactating. One of my DH's friends started lactating due to a condition and wasn't at all pleased when the doctor reassured him it was safe for any potential babies to drink!
Again no comment on the trans thing. Just saying "men need to take chemicals to grow glands" is rubbish and makes us women sound like total idiots. It's induced by the same hormones that make women lactate.
I also know a woman who couldn't lactate at all, and had to take probably the same mass quantity of estrogen and progesterone a trans man would have to have. Was she poisoning her baby? No, I doubt so. I prefer research to Mumsnet.
That said, I think whether for men or women, there's probably still some risk. It's stupid, ridiculous and vain for both genders – assuming people are doing it on purpose (rather than the article exaggerating cases that are the result of hormone therapy that's already occurring, not that I support hormone therapy but it is what it is).