I’ve used Disney+ for several days now, and I’m unimpressed. Signing up was a hassle - it wouldn’t let me do it on the app. Once I had everything set up, I decided to look through the content. My first observation is that the sheer amount of shows and movies not originally made by Disney shows just how much of the film and TV landscape they’ve swallowed over the last decade or so. Second is the fact that many shows have episodes or entire seasons missing.
About the first point, it's entirely possible that some shows were made by Disney for other channels, especially before they owned ABC. So that might explain the occasional NBC, CBS or non-20th Century Fox produced FOX show on there.
About the second point, I know Simpsons has one episode missing, they banned the one with Michael Jackson in it, Stark Raving Dad, recently. Won't shock me to discover similar cases where an episode is omitted because someone who's now disgraced is in it.