Yeah, obviously. The more interesting conclusion is the opposite though. With windifference 5 you'd have to account for both maps and teams on top of elo, to even get a basic idea of rounds played.
I wouldn't want to do that, whereas adding scaling to k takes a few seconds and then a bit of trial and error.
So I'm not sure if "expected rounds" really adds anything to the stats. Most of the time it's going to be wrong. Winning chance seems like more than enough information.
Or do you plan on making the expected rounds more accurate? Imho it would be a bit overkill.