Yeah, I still think it could be a shorter arc. I'm going with 21-35 chapters-ish.
Depending on what the Gods Knights are here to do, this could be a really sudden and brutal ending. Maybe with Luffy freeing Loki just to get some backup against these guys.
I could see it going longer, but part of me feels like Oda added the whole "Don't linger here too long" thing on purpose. I think he's ready to move on to other things, too.
Part of me is wondering if Oda's using the "Elbaph Silhouette" guy as a sort of "progress marker" for the arc? When we first saw this guy in Chapter 1124 he was on the left side of the page. And the next time we see him in Chapter 1132, he's around the 1/3rd mark on the right... more or less in the "center" of the page. I just wonder if Oda is using that to indicate that we're actually between a third and halfway through this arc already? So, it's possible that this guy will finally slowly make his way into the story sometime around Chapter 1140 or 1148 or so, just in time to essentially end the arc. But, I'll admit this is stretch. Still, I think this guy getting revealed will probably signal the end of the arc, more or less.. We started by teasing this guy, we'll probably end Elbaph by revealing who this guy is.
I will admit, I'm less sure than I was at the start of this arc. But, I'm still leaning towards this being a shorter arc.