I am an advocate of the Nokia Test, up to a point.
Why do I like it? I think it is a simple way to set some sort of lower boundary on Agile (Scrum) and it tends to make two problems more visible: Cowboy Agile on one side and Agilefall (aka Wagile) on the other side. Cowboy Agile is where you are doing stuff you are making up on the fly (mainly not doing things you personally don't want to do). Agilefall is where you are doing Waterfall (or mostly waterfall) and calling it Agile (or Scrum). [Alert: Those are my definitions of those terms; others may proclaim somewhat different definitions.]
If the Nokia Test causes people to say, "oh, gee, maybe we aren't really doing Scrum", I think that is a good thing. Especially if they think about it, and decide to do Scrum better.
As with almost anything, it can be misused.
As one example: If people use it as just a checklist, and say "oh, we have 'em all checked off; so we must be doing Scrum well", that would not be helpful. In my opinion.
The Nokia Test only defines an absolute minimum set of things regarding Scrum.
Use the Nokia Test to start some conversations around "Are we really doing Scrum and really getting value from it, or are we just playing at Scrum?"
Passing the Nokia test does not say you are doing Scrum well. Among other things, to do Scrum well, you must really understand the principles and the values of Agile. So, for example, the Nokia Test does not talk about principles. The Nokia Test, in my view, does not even cover all the important practices.
So, it is a test more to determine who is NOT doing Scrum than who really is doing it. It establishes a lower guard rail; if you touch it, you should think a bit.
What does it mean to fail the Nokia Test? Well, whatever you are doing, you should stop calling it Scrum. Does failing the test say you are "bad"? No. Does failing mean you are less productive than before? Not necessarily in my opinion. BUT...although you might be more productive than your waterfall days, I think you are likely to be quite clearly less productive than you could be if you followed Scrum a good deal more closely.
One final thought. I really think using Scrum well can make your teams a whole lot better. But the real point of Scrum is not to brag "I'm doing Scrum just as they told me", but to say something like "Scrum is helping us produce a lot more business value each month....". You should want to do purer Scrum to get more business value, not just to be a purist for its own sake.