While that may not be unusual for other companies, Disney is not in the business of doing that.
They've bought the franchise to help bolster their portfolio of characters, and the teens (and older) demographic is something that they haven't been able to crack. So they're not likely to ditch it any time soon, nor risk what it has going for it by meddling.
I agree, the first two rides you mentioned have little theming and are primarily down to names.
Spiderman is a little more complex, but it won't be that difficult to have another set of characters in the ride.
That is if Disney were to play hard ball and want Universal to remove them when the contract expires (which is probably a way off). They could very well negotiate a contract extension and just sit back and let the money roll in from their rivals.
Its a genius move.