It would be great to at least see a little bit of various recurring segments in a montage. I wonder if they would build such sets that would only be used for a few seconds in a montage (I know, they could just green screen and cgi the backgrounds). I'd be surprised if any of the classic sets still exist.
In the previous movie they didn't rebuild any of the classic on-stage sets, except for the Swedish Chef's kitchen (I wonder if that was intended to be his set as used on-stage or if it was supposed to be the canteen, only looking like the kitchen). We didn't get Pigs in Space, Muppet Labs, Vets Hospital, or any other recurring sketches. In fact the telethon didn't include any sketches. We got a few musical numbers (with some great but simple-looking sets built), a comedy monologue from Fozzie, and an act from Gonzo. The non-musical numbers used simple backdrops.
I wonder if this film will be as nostalgiac/full of fan service as the previous film (and I feel the previous one could have used a bit more fan service). I feel it made sense for the previous film, as it was promoted as their comeback, but I wonder if that'll be neccessary for this film. With the Muppets on a world tour they'll surely include many characters like the last one.