Maybe its regional or cultural but the FTM trans I know well wouldn’t object to being referred to or lumped in with pregnant women on a general basis and if they did they are fully capable of correcting those refering to them with whatever term suits them.
Cool. Whatever works for them.
But it’s worth being aware that as you’re not trans yourself, the whole “I have trans friends who are ok with this behaviour many trans people feel is problematic” just sounds like the same excuses bigots have used over the years. “I have black/trans/female friends who are ok with <insert problematic topic>”.
Secondly, even if you are accurately representing their perspective, no one is taking away anyones right to identify with whatever terms best work for them. The issue is not pushing terms on to others who don’t want them.
Your friends can identify with pregnant women all they like, but it becomes an issue when trans men who don’t share that stance get told that they’re the problem