Yep, you assume correctly.
The problem is that his fiancee's two friends also have objections to this. It puts them, his fiancee, and him in a very awkward position.
From what I've gathered so far this seems to be an unusual request for the rabbi of a Conservative shul. Apparently the rabbi, personally, is himself Orthodox--what he's doing
as rabbi of a Conservative shul I don't know. But the fact that he is himself personally Orthodox. But this seems to be something the rabbi could have told them about this more in advance--they have all their arrangements (ceremony/reception) thru that temple, so it's a little late in the game to go somewhere else--to say nothing of the fact that his future mother-in-law is President of the Sisterhood there, and his future father-in-law is Temple vice-president.
What makes my friend teed off is that this rabbi has no problem sitting at a table at the reception with women, and has no problem going to a reception where men will be dancing with women. And a couple of their friends will be women dancing with women, for the matter. That he's got no problem with, but he's insisting on something that is offensive to the groom and two of the bridesmaids? I call that hypocrisy, sorry