It's actually the complete opposite.
TOTK is a bigger game than BOTW, launched to a bigger userbase, has more WOM given the traction of its launch, and the franchise is more popular than ever. All of which will ultimately lead to it being leggier than it's slower selling predecessor.
Suggesting it needs to prove to have BOTW's legs is akin to saying that GTA5 would have to prove to have GTA4's legs when it got off to a much faster start in sales (GTA 5 also launched at the end of PS3/360's lifecycle and wound up selling much more than GTA 4).
Like I said, this will be a game Nintendo consumers will buy in droves for the better part of the next decade. There is nothing to suggest otherwise. Buckle up.