A few things, my "2 cents" if you will:
- This came out soon after the Digital Foundry article, and Digital Foundry is known for relentlessly bashing Nintendo and the Wii U since it gets them attention. I can't prove anything, but it seems a bit suspicious that this comes out right after, and pretty much seconds what DF said with more detail.
- I'm a licensed Nintendo Developer and have access to all the specs of the Wii U as well as a dev kit and other things. Some of this stuff doesn't sound true. Even the GPU stuff seems inflated as if though someone skewed the article to make it seem like they weren't bashing it by speaking well of the GPU. I can't attest to the development of any of the 3rd-party games and how good support was, nor can I go revealing any details on specs as I signed an NDA, but I can most certainly say that I'm taking this with a grain of salt. It could be true, it could be partially true, it could be totally false. My bets would go on the 2nd one.
Overall I just find it sort of fishy and suspicious. Indeed, an anonymous developer and only one developer at that, that's hardly a reliable source where I can start jumping to conclusions.
Ultimately though, as a gamer the most important thing to me is that the games are "good", i.e. enjoyable; as a developer, the most important thing to me is documentation and easy access to support, both of which Nintendo have done a great job with. Perhaps things have changed since then or the circumstances or other details were different, I can't be sure, but I am sure that it's never safe to take anything like this to be totally true, whether it's positive or negative.
tl;dr
Don't overreact, that's exactly what whoever made the article wants you to do. =)