Nintendo of America has removed all product listings for Nintendo DS and Wii games released in the past from their website.
The removal does not affect any Virtual Console games released on Wii U, so it is still possible to find the Virtual Console listing for games on the website. It’s also still possible to find Nintendo Switch, Nintendo 3DS, Wii U, and smartphone games on the official NOA site.
NOA only at the moment
We also have to point out that the official Nintendo websites for Japan and Europe have not removed any Nintendo DS or Wii listings yet.
Why? We are unsure as keeping the information available should not harm them in any way or form really. And we ourselves would rather encourage keeping the info available. But Nintendo sometimes works in mysterious ways.