Where in the world did you get that from? If the Marvel deal happens, they're using Spider-Man within the next two years in all likelihood. They wanted him for Civil War, and the latest rumors are that Spidey could still cameo or get a credits scene. All signs point to Marvel's Spider-Man showing up annually if the deal happens (the second new Spider-Man is to be released in 2019, meaning the first would be in 2016 or 2017, plus they want him in Civil War and Infinity War). Sony wasn't even planning to release TASM3 until 2018.
Also, hate to break it to you but there's less than a fraction of a percent chance TASM3 happens even without a deal. Ignoring the Marvel stuff, multiple Sony documents reveal they were planning on rebooting on their own if an MCU deal didn't happen. One exec even wanted/wants Ryan Gosling for Spidey.