I think that he means that Disney is not just a movie company, it also owns other things. Like rights to songs and TV shows. That's kinda like saying that Dreamworks is JUST a movie company but they also have a record label. Although, Dreamworks could do a lot of things to the Muppets since they really don't have a lot of things going on, they could produce them and maybe do more things with them than Disney does. Here's the point, they don't own the songs off of TMS, they just own the Muppets franchise. Those may not include all the songs, they would have to clear them with the songwriters or their family.
Daniel