I recently found one article called "All Animation is Disney", which lists examples of people thinking that Disney is responsible for all animation, and it says that one of the few companies that doesn't get mistaken for Disney is Warner Bros., but then many slapstick cartoons from other companies get mistaken for WB. But I've known a few people who have mistakenly thought Looney Tunes were Disney. A few people have asked "are Looney Tunes Disney?", one in boy scouts we were playing Outburst and one of the cards said to name Disney characters and a few kept shouting out "The Looney Tunes!" And once I talked to my grandpa about how I read about how when the Mickey Mouse version of The Three Musketeers was pitched, they initially had trouble because the original story actually had four musketeers and Disney couldn't think of an appropriate fourth musketeer to go along with Mickey, Donald, and Goofy, my grandpa said they should have used Daffy Duck.
I wonder if any of this confusion comes from the fact that many Looney Tunes characters appeared in Who Framed Roger Rabbit, though I never hear people referring to non-WB characters who appear in that movie (Betty Boop, Woody Woodpecker, Droopy) as Disney. Droopy also appeared in the three Roger Rabbit shorts but despite that I haven't heard anybody refer to him as Droopy (of course I wouldn't be too surprised if I don't know many people who are too familiar with the Roger Rabbit shorts, except maybe Tummy Trouble). I don't think I've ever heard anybody refer to any other non-Disney cartoon besides Looney Tunes as Disney, and yet the trope page claims people don't make that mistake while mistaken other animation for Disney. Maybe it's wrong, maybe I know the only people in the world who make the mistake, dunno...
Considering that, I'm surprised TV Tropes doesn't have a "All Puppets are Muppets" page. I know there is a trope page called "Muppet" which refers to all puppetry that resembles Muppets, whether it is Muppets, creations from the Jim Henson Company, or unrelated. I see more people mistake non-Henson puppets for Muppets more than I see people refer to non-Disney animation as Disney. The recent "Million Puppet March" event was originally titled "Million Muppet March" yet was intended to involve any kind of puppet. Lots of people mistake Yoda for a Muppet (and I rarely hear of any similar mistakes regarding other puppet/suit characters from Star Wars, though in Clerks they thought "all Jedi had was a bunch of Muppets"). Back when I was younger one of my friends thought Barney the Dinosaur was a Muppet (I knew better, even when I was 9). On the "that guy with the glasses" forum there have been some request threads for top 11 Muppet lists (not sure if those are still on the forum, as the whole request thread had been deleted... not sure if they can be re-added now that The Nostalgia Critic is coming back) and on those threads people made mistakes (I corrected them but it seems they didn't want to accept my mistakes), thinking that Audrey II and the Jabborwock from 1985 Alice in Wonderland are Muppets.