Nah, it'd obviously be Samus Returns Rising: Revengeance.
It's one of those things we can't confirm unless there's definitive evidence from the man himself. But Sakurai probably settled on Ivysaur early - not just since it has some design overlap with Venusaur*, but also since it might be easier to implement than Venusaur might've been. Yeah, Venusaur's flower might be useful for attacks like Solar Beam, but that might be a bit more difficult to implement than Charizard's wings or Blastoise's cannons.
* (For instance, Ivy can still use vines and its bud can still release spores - both of which Venusaur would presumably do as well.)
Also, re: The Switch OLED:
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