I've said before and I'll say again now: There are two different things that we talk about when using the term "Disney". They are very distinct but get conflated because both use the term "Disney".
One is The Walt Disney Company. This is a multi-national entertainment conglomerate. Marvel (and Lucasfilm, ESPN, etc.) is absolutely part of this. Obviously -- the company owns those properties. So they are part of the Disney company umbrella.
The second thing is the Disney brand. That is more nuances and indistinct, but generally covers things closely related to the historical Disney company founded by Walt and Roy. So, the animated movies, the theme parks, films like Mary Poppins or Herbie the Love Bug, etc. Some would include Pixar in this, given how tightly it has been associated with the core Disney brand, and because it seems to share the same "family entertainment" values. I would say very definitely that this Disney brand does not include Marvel or Star Wars or ABC/ESPN, etc.
They are two different things. Both are referred to "Disney" in the shorthand because, well, we refer to things in the shorthand. But I think it is very obvious that when people speak of and refer to the Disney "brand" that they aren't talking about Marvel. And I think this is reflected by the company not using the castle in front of those films -- they want that line to haven identity separate from that of the core Disney brand. Now, mind you, they want people to recognize that it is the Disney company putting out those massively successful films (and corresponding consumer products) but that's a different situation.