Had an idea, but it probably falls flat as Sony probably owns the rights to Miles also, but basically, Sony said Marvel could use Spidey for 5 films. So they did. Now on this last one they're making the Multiverse. MCU Spidey could go through the Multiverse and be "trapped" at the end and wind up basically in Sony's Spidey Universe timeline with Jared Leto Morbius and Tom Hardy Venom and be able to "explain" it film wise while Marvel could use this opportunity to present Miles from another Multiverse and make him the new full-time Spidey in the MCU.