You realize that it is probably going to cost around a billion or so dollars (maybe not that high but it is going to be very costly) for Disney/Marvel to regain the character rights? If this one under performs, Sony will merely wait another year or two and reboot it with a different director and writer and keep doing this so that Marvel is denied a chance at buying it back.
Actually, they don't need to buy it back. The rights would revert back to Marvel automatically if Sony wasn't using them for a couple of years. But yeah, they'd probably try to produce at least one more reboot before they'd let that happen.