Trans men do most definitely lack power. They are not pandered to and platformed to anything like the extent that TW are. Some accounts from detransitioners describe how they are exploited for sex by straight TW and other straight men (who know exactly what sex they prefer). As a TW you’ve been able to gain access to females in prisons, hospital wards, changing rooms etc, allowing predatory men to carry out attacks, flashing and other crimes, as well as being given women’s sports to exploit and gain from. But the only loophole where being a TM could give you an advantage, sexist primogeniture rules, has been closed PDQ.
However, even though “pregnant people” arises out of the belief that TM are men and that therefore men can be pregnant, it also serves to confuse, as people think of TW as men and that therefore it means TW (actual men) can be pregnant. It encourages the confusion in the NHS where actual males are treated as if they could be pregnant and it encourages the fetishization of female bodily processes by males, so you end up with males in breastfeeding groups and similar which destroys them for many women.
it is also downright rude and insulting to women. Only women, actual women, get pregnant. The fear of saying the word “woman” because a small group of women who choose to deny their womanhood might be offended, not giving a shit that huge numbers of women who are proud of their womanhood might be offended, is discriminatory. But more to the point it pisses women (and quite a few men) right off and when someone stands up to it publicly they’ll get a lot of support.
If trans men don’t like it, maybe they could lump it, since saying “pregnany woman” is in fact a reflection of reality? If they can’t face reality that’s their business but leave everyone else out of it. And BTW if you think you are “living as a man” while popping out babies you may have got the wrong end of the stick.