That wasn't how it used to work with long outdoor lines though (e.g. FOP). Pre-Covid, for example, we could walk up to the FP entrance, get the swap pass, then I'd take off with our youngest while DH would go to the back of the line. I don't understand the comment about getting the swap pass and not waiting in line. It's not like DH could "cut in" the standby queue at the FP entrance, the CMs are right there and would see it so of course he had to go to back of the "real" line after getting me my pass.
I think it is more about them not wanting a crowd to form at the FP entrance with people trying to get swaps. If they make you wait in line, they process the child swaps as you move forward in the line one at a time instead of having people cluster with no distancing.
At least you can take your stroller through the outdoor queue.