The O5 aren't from the past, they're from an alternate universe
- They seemed to be from the 1960s, but due to Comic-Book Time it should have been the 1990s at least. Perhaps it wasn't the past of Earth-616, but rather, another reality entirely - and the reason they can't go back is because it was destroyed by an Incursion, similar to Spider-UK's fate.
- Alternately they were originally from the past but the aftermath of Secret Wars changed that.
Jean TP'ed Laura and Warren together
Jean was feeling threatened by Scott's attraction to Laura, and how the two of them were beginning to connect. She therefore telepathically pushed Laura and Warren together in order to protect her "territory." This is why Warren suddenly showed interest in Laura following the Trial of Jean Grey arc after having not interacted with her at all prior to that point.