No Avira it’s unusual because R Moshe ignores or argues with the vast majority of achronim who have dealt with the issue. This is not unusual for R Moshe kdarko b’kodesh but generally other poskim didn’t Pasken in that style
The tzitz Eliezer is more “grounded” in chain of mesora going through achronim.
To be clear. Of course R Moshe could, I am not chas veshalom questioning his psak chas veshalom. Nor am I choosing who to follow. I am just relaying that in practice R Moshe is not followed in this regard
“I think “most rabbonim” quoted here refers to shul rabbis and communally involved modern Orthodox or black hat wearing religious zionists, to be honest.”
In my experience, shul Rabbis don’t deal with these questions. They start at the ob gyn and go straight to the relevant poskim if chasidish then chadidish yeshivish then their community (I’m not as well worked in modern orthodox community though I doubt shul rabbanim get these questions there either)