Remember X-Men: Battle Of The Atom? Of course you do. There was a first issue that focused on the All-New X-Men, colloquially known as the O5, standing for the Original Five X-Men. And what happened when the young Scott Summers was attacked. And then healed.
Establishing that the O5 were part of the same timeline as the current X-Men.
These are not the O5. they are the Faux 5.
And they always were.
I bet they're going to go with the Secret Wars collapse of continuities and remaking in its wake.
Although that won't explain how the Hydra time loop survived it…