Lorna's there to look for Alex, who we learn has fled the X-Men immediately after issue #66, scared at himself for nearly killing Bobby. He's chilled out since, joined the counter-culture and started reading the Whole Earth Catalog (worth a read if you've not heard of it: it's odd now to think that people would accuse NASA of hoarding pretty pictures rather than milking them for all they were worth). And so we discover that although X-Men: The Hidden Years is pretty consistent with the X-Men comics, it simply doesn't fit with the other stuff from the interregnum. The Marvel Chronology Project puts this issue after the entire run of Hidden Years, which seems to be pushing it, frankly. Alex agrees to come back with Lorna, eventually.
This is a much better attempt at doing a "look! the hulk and the X-men share much of the same tragedy!" thing than #66 or even #40. But still, it's mostly full of smash.