The AMCs I go to it's only been 1 refill allowed. They may have stopped either the drink or the popcorn on the free part can't remember; I know one of those is still free just can't remember which or if they still have both. The only ones that still get unlimited refills is when you order the popcorn inside Fork & Screen or Cinema Suites.
I'm not sure how they would prohibt based on movie type unless they made you show your ticket stub (which often ours are just the QR code on our phone) and the person behind the counter knows that movie has an intermission. Mom and Pop style places for sure I could see being more restrictive.
It's a good thought though for sure. Makes me wonder just how long of an intermission they are thinking. A 5min wouldn't be long enough to do much, 10 mins probably not either if everyone just swamped the bathrooms and concession stands, 15 maybe but then you're looking at the time commitment people have when you count in the previews..ah heck we're probably looking at 4 hours anyways
(halfway joking).
Who knows the way the whole vibe of the movie is I just may need that intermission to get a quick breather from all the deep stuff going on in the movie.