The idea would never clear an ethics board. There are too many variables that can go wrong, with another life on top of that, and potential mutations that can be passed down from their children (this specifically is why cytoplasmic transfer aka 3-Person IVF was discontinued). The real catch though, is that there's no compelling need for male pregnancy; if there were, you could possibly justify the dangers ethically.
Inherent and implicit in any argument about male pregnancy is the impact it would have on the host's sense of gender identity. Calling it "male pregnancy" ignores the very real issue that men who identify as "men" aren't going to want anything to do with it. Everyone bringing up the idea of male pregnancy seems to neglect that such a thing would cause horrible gender dysphoria; either that, or they believe in the Tumblr narrative of "you can be anything you want". Or they don't understand that everyone has a gender identity whether or not they're trans and that screwing with it is asking for trouble.
"Male pregnancy" should be more like "transsexual female pregnancy", because the act of pregnancy causes the body to feminise radically and become awash with hormones required to sustain it. In fact, MtF hormone replacement therapy explicitly mimics pregnancy in male-bodied individuals. Your response to female HRT as a male-bodied individual is considered a litmus test to decide whether or not you should be on it; if you begin to feel more confident on HRT, you're trans. If you get sicker, depressed, and suicidal (like Alan Turing), you're not trans. And to most real-males who would get pregnant (in fact, I would say all of them), the act of pregnancy would be horrific and devastating mentally.
So, in the end, it's kind of nonsense to even suggest "male pregnancy", at least from the perspective of someone who is trans. If you would seriously consider undergoing male pregnancy, you're anything but male.