Not really referring to rights but more of over-saturation.
If Universal wants to be seen as equal to Disney, I feel like they need to move passed IPs that have been consistently used at Six Flags and other lower tier theme parks.
There are over 400 amusement parks in the US. 6 of them having had rides based on the same IP is a far cry from over saturation.
And who is determining if Universal is equal to Disney? Us the Theme Park fans? Or do you mean in the eyes of the general public? Because I can tell you, the majority of the general public that visits Disney and Universal are probably unaware, or no longer even care, that a few regional parks once held a Scooby Doo attraction that chances are they never even rode.