Sony just want the revenue I'm sure they dont think they can top it but probably think they can coast it off the MCU success. Folks keep missing that, Spiderman didnt do well last time they put it out but that was compared to the OG trilogy, it still had hella profit and made Sony money. Mfs all in a bunch at the idea of Sony holding a stronger foot to make Feige and them to give In if it's true Spiderman was penciled into the Avengers next main plot if the RDJ plot was to evolve into that and come full circle which completely makes sense.
Point being Sony dont give af, they either want all the revenue off their movie or majority of it off MCU. Sony it's own enemy but I feel they got leverage here if Spidey important to their next story.