The destroyed Leopardon being rebuilt and upgraded makes perfect sense when you think of Tokusatsu and Super Robots: how often is a hero's mecha wrecked but reconstructed to better fight the new villain?
Also, Considering that Leopardon's original suit was stolen, Marvel actually finally gave it the Mid-Season Upgrade it could never get!
Fridge Logic:
In the Epilogue issue, Karn mentions that the reason why Peter and Otto, who are from the same universe, can be on Loomworld (Earth-001) simultaneously is because of special physics of that world that allow for manipulation of reality to that degree. However, they also crossed paths on Earth-13 in issues 10 and 11 of "Amazing Spider-Man", which did not have any of those changes.