This is a very close adaption of Giant-Size X-Men #1 from April 1975 which saw the debut of the all-new, all-different team who took over the torch from the classic X-Men.
Although season 1 was very cautious on adapting the early issues and transport them into a modern era, mentioning mobile phones and the likes, this episode feels like being set in the era it was released (the 70s), even dismissively mentioning Colossus being a "Commie" by Iceman.