Gaming

Your hypothesis is that Nintendo, one of the most litigous companies on the planet, that routinely shuts down infringing projects during development, saw that trailer and made no attempt to investigate whether that game might infringe their IP over the last two years?

But the trailer did not contain any copyright violations or IP infringements. Now the game is out, with lots of content and a huge world, a deep dive can be done and checked every detail if anything violates something. And the game is commercial and out, and the evidence is in their hands if there is any. This can't be done with just 2 trailers showing 0,05% of the game and content. With the game in their hand, they can compare models exactly in example.

I personally don't think there is any violation here, but I am not here to judge. I just wanted to explain that this deep dive could not be done in the prior 2 years before.