Not so much a little thing I've noticed as much as something I recently realized.
Shortly after I first saw Muppets from Space, I said that it was the best of the post-Jim Henson movies, and shortly after I first saw The Muppets' Wizard of Oz, I actually thought it was better than The Muppet Christmas Carol and Muppet Treasure Island (really!). But now I feel like MCC is both the best of the 1990s Muppet movies AND better than MTI and The Muppets' Wizard of Oz. That's not the thing I just realized.
MFS and Wizard of Oz were both big deals in terms of recasting. We got to not only see Scooter for the first time since 1991, but he was even given a full line. And we also got brief dialogue (though not more than a word each) from Dr. Teeth and Rowlf, though both had gotten new dialogue before this (at the time I hadn't known that John Kennedy voiced Dr. Teeth in Days of Swine and Roses, and thought this was his first post-1990 vocal appearance). And The Muppets' Wizard of Oz has some new recasts as well. It's the first major Muppet production since Jerry Nelson's semi-retirement, so we hear new recasts for Floyd, Crazy Harry, and Camilla (in addition to previously-heard recasts of Lew Zeland and Statler), it's Eric Jacobson's first performance as Sam (and one of his first vocal performances as Animal), Bill Barretta's first performance as Dr. Teeth, and it ended up being the only time Rickey Boyd performed Scooter (it was so good, impressing the Muppet performers, I was surprised this recast didn't stick) and Tyler Bunch performed Janice. Most of the Jerry Nelson/Richard Hunt recasts here didn't stick, and the recast dialogue varied from a lot of dialogue to brief dialogue to dialogue cut from the original broadcast version, but it felt like a big deal (even if there were more recasts/vocal appearances by these characters during the time between these two productions).
But The Muppet Christmas Carol also brought on new recasts, and I didn't really think of it being a big deal until today. Coming only a couple of years after Jim Henson died, it was one of Steve Whitmire's first major performances as Kermit, and the first time we heard the recasts of Statler, Waldorf, Beaker, and The Swedish Chef, and with the exception of David Rudman as Chef, all of these recasts have lasted a long time. Many of Henson and Hunt's characters were kept silent or absent at this point, but these characters got to be heard with new dialogue in 1992 (though it seems like we had to wait three years before Statler and Waldorf's next appearance).
But the difference is that I didn't know the Muppets were puppets until about two months before I saw MCC. I knew Jim Henson performed Kermit and had died by then, and I didn't think recasting was a big deal. Many classic iconic animated characters from Disney, Warner Bros., Hanna Barberra, and other studios were recast, and it wasn't until a few years after I got the internet that I heard about them being selective in recasts, I saw some things that mentioned animated characters being recast and didn't quite follow what they were getting at with not recasting many characters (not really realizing that the voice was only a small portion of the characters). In fact for several years after MCC I wondered "who performs Rowlf, Scooter, Dr. Teeth, Janice, Link Hogthrob, and other characters from these performers?" without thinking much of the fact that many hadn't gotten new dialogue (and Scooter was non-existent) until shortly before I got the internet and realized they just might not have recast them.