I suppose you could do that. It would be silly to think that you could not use the items learned in Genesis on Genesis. Could you imagine doing missions all day only to line up at the Ob or whatever transfer mechanism and return to your home map? Seems unlikely to me and frankly unappealing.
The description on Steam:
GEAR UP AND BUILD UPAs you brave the many dangers of ARK: Genesis, take some time to craft new gear. Wield weapons like combo-capable plasma claws and remote-guided cruise missiles. Make tools from fishing nets to mining drills, or new vehicles such as hover-skiffs. Build interactive structural elements such as pressure plates, alarm systems, jump pads, ocean platforms and more. Whether you’re a go-it-alone survivalist, a weapon-making warmonger, or a base-building architect, this expansion has a crafting project suited for you.