Update - It seems there's some confusion here, as the site linked with the information isn't actually the official Nicalis site. That said, the listing does still show Wii U as a supported platform on Nicalis.com. The thing is, the site that lists the game as no longer coming to Wii U is hosted by someone that actually has had ties to Nicalis in the past. Long story short, we're still not sure what's going on, but perhaps the Wii U version isn't dead yet. Thanks to dark weres for the heads up!
The official Nicalis page for 90s Arcade Racer reveals a few things. First off, the game had its name changed to 90s Super GP. On top of that, the title is now listed for PS4/XB1 release, but there's no mention of Wii U. We'll try to get some information on this as soon as possible. Thanks to NintenDaan for the heads up!