Destroying the confidence Disney was trying to build into Marvel as their owners.
And to my reading, that would also open up a potential breach of contract on Disney's part, just by having Walt Disney World and Downtown Disney existing. Universal gets access to
"The present inventory of the Marvel characters is set forth in the schedule to be attached or provided by Marvel promptly after execution hereof, plus any characters developed or acquired or licensed in the future by Marvel which (x) are marketed under the Marvel “Banner” or (y) were previously marketed under the Marvel “Banner” during the term hereof and are subsequently marketed under the “Banner” of a Marvel Related Company (defined below)."
and
"As used herein, a “Marvel Related Company” shall mean any entity that is owned in whole by Marvel or (i) in which Marvel (or a company in (iii), (iv) or (v) below) has at least a 25% equity interest, (ii) Marvel (or a company in (iii), (iv) or (v) below) has a significant board representation, (iii) is a parent of Marvel, (iv) is controlled by an entity which (directly or indirectly) controls Marvel, or (v) is an “affiliate” of Marvel as defined in the 1933 Securities Act."
I think Universal would have a point if, being told to use the term "Disney's Marvel", that the Disney characters are now included in their exclusivity agreement.