Oh without a doubt. I killed that shit as soon as I saw 5.5.1 in the system settings. I was PISSED though.
The problem is the fact that at least two large threads included seemingly very informed initial posts describing that you can block updates by using the tubehax dns. So people come in looking to find out what they should do and when the reach the part about how to prevent updates, they don't see "DELETE ALL INTERNET CONNECTIONS ASAP!!!" they see "Use tubehax dns! It works!" when it clearly does not anymore. Unfortunately by the time you figure out it doesn't work, you are already updated.
I agree - there's an awful lot of misinformation being spread through these threads that offers people false reassurances. A DNS will never be fool-proof because all Nintendo need to do is force an update through an unreported URL and people find themselves updated.
Please people, don't risk it. Not until we get proper spoofing on 5.5.0