If BOTW needed 2 million to break even then that would make the budget 120 million. I doubt BOTW2 budget is as high since most of the assets and engine are made. Nintendo likely has some very modest budget compared to Sony first-party games. BOTW was probably their most expensive game by a large margine. Here I am remembering when the $70 million Shenmue in 1999 was the most expensive game ever made and kept that record until sometime in the 7th generation.
Even for first party Nintendo don't get 100% of the game revenue, because of retailers and other costs (like distribution). I think 60-70% is a better estimation, BOTW budget was probably something under 80 million USD