I think there'd be a lot less viable Pokemon than you think.
A TON of Pokemon are reliant on TMs/HMs for their movesets, most learnsets are trash in gen 1. Tauros' best attack is Stomp, and has no coverage. Rhydon has no STAB. Moltres' only Fire-type move is Fire Spin. Chansey only has Normal coverage. Need I go on?
It could be interesting, but basically everything is going to centralize around the 3 best Psychics (Alakazam & Starmie still have recover, Jynx still has Lovely Kiss) & the most viable of the precious few paralysis inducers left (Jolteon, Dragonite, Snorlax, Lapras, Jynx again EDIT: also Tangela, Eggy, Victreebel & Parasect, forgot about the Stun Spore mons some reason). The rest would be the few Pokemon remaining that aren't completely screwed over by their learnsets (such as Zapdos, Porygon, Pinsir, Golem).