So Marvel states there is enough room for Legacy and the new versions.
Well this isn't the first time we've been lied to. How long do you think they will maintain Legacy and New Versions before retiring any of the characters?
Does the MU need TWO Hulks? Banner and Cho? Last I checked the Doc Green version made sure the other Hulks were cured, so once Banner is back how long will he allow Cho to run around as a version of the Hulk?
Two THORS? Well we've had two THORs for years considering that Beta Ray Bill wields the same power as THOR. But he wasn't rammed down our throats like Foster Thor has been. If she survives and is cured or gets another hammer while THOR reclaims Mjolnir, how long will that last? They may date for awhile and fight together but inevitably the old "there can be only one" rule will come into play.
So lets have Marvel borrow a page from DC Comics. DC keeps the Golden Age characters on Earth 2 and the main characters on Earth 1.
Marvel creates an alternate universe, perhaps an Earth where its heroes are all dead or in hiding and the villains have essentially won. Now the new versions of the heroes get migrated to that world and decide to stay there and make it their home and free the planet from evil. The originals stay on the MU earth and all is right again.
Miles & Peter are doing fine (and Ben, if you count him).
Kamala & Carol are too... well sorta.
I don't really buy "there can be only one."