People get why it’s ridiculous to assume Spiderman or Wolverine or anybody else is going to be in subsequent Avengers movies or comic book crossovers right?
I feel like I’ve been explaining this a LOT lately. In 1997 Marvel Studios (a subsidiary of Marvel Entertainment in charge of coordinating with film studios to create Marvel character-based movies) started to sell film rights to titles that would eventually become movies like X-Men (2000), Spiderman (2002), and The Fantastic Four (2005). These rights were only for the depiction of the title in film, but encompassed all the stories, main characters, villains, special items and environments. Studios like Fox, Columbia, and New Line Cinema produced and released these films, in coordination with Marvel Studios.
These movies did so well (and Marvel got so frustrated dealing with film studios) that Marvel Studios decided to start making their own films. Marvel Studios would produce films for the characters that Marvel still owned the rights to: Iron Man (2008), The Incredible Hulk (2008), Thor (2011), and Captain America: The First Avenger (2011). Marvel Studios was able to include these characters in The Avengers (2012) because Marvel owned the rights to the characters. Spiderman, for example, couldn’t appear in The Avengers because Columbia Pictures (a subsidiary of Sony) still owned the rights to the film depiction of the character. Marvel has been able to buy back some of the film rights (Blade, Hulk), but a few major names still are under outside control. So, unless Sony or Fox allow it (which would cost Marvel an enormous premium), neither Spiderman nor Wolverine are going to appear in any films created by Marvel Studios any time soon.
Ownership Map is above, if you don’t want to waste your time reading.