They get a whole bunch of IPs currently appearing at Universal! It might solve their Movie-Spider-Man problem, but it won't solve their park-attraction-Spider-man problem, and only give them more IPs they can't use in their parks.There could be a transfer of control clause...so that if it is sold, they can renegotiate/take back the rights. There wasn't a transfer of control clause for the Uni rights, so I doubt there is one here.
If Disney could somehow extricate Playstation and the Entertainment divisions away from Sony proper, this would be a more appropriate sized purchase than Netflix. They get tons of IP, including Spider-Man and a major foothold in streaming user households.