Yeah there's a lot of truth to that, I'm not sure how much of Peterson's appeal is actually due to his own work and how much is just because he's kind of re-introducing the work of philosophers like Nietzsche.
I haven't read into maps of meaning, mostly because of the writing style that this article criticises rather well, but I have seen some of those diagrams within context, and they do actually make sense when they are (some of them at least, not sure they all do. Actually I'd be quite surprised if they all do).
Also whilst that article is correct in that it's very easy to interpret Peterson's writing in a number of ways the writer takes a lot of quotes and again presents them with no context, thus making the interpretation a whole lot more open. And they simply make some mistakes imo, for example:
“People do not care whether or not they succeed; they care about whether or not they fail.” Which is apparently different.
There is a pretty obvious distinction between caring about success and failure, success cannot occur unless one makes an attempt so succeed, whereas failure can only occur if one makes an attempt to succeed. So if it is true that people care more about failure than success you would expect that people would be less likely to make ambitious attempts than if the opposite is true. Obviously there's a debate to be had about how useful that generalisation is, or whether it is even true but that's a different question.
Personally I think Peterson's self help kind of stuff is very useful and it seems to be insightful, but I do find it very unfortunate that it blends into his political views so heavily. An emphasis on individual responsibility and self improvement is great for individuals (and yes society is ultimately made up of individuals) but I don't think completely ignoring groups at a societal level is a great idea. I do agree with him politically in the sense that we need to be more open to discussing a whole lot of topics and that we actually need to take a more detailed analytical approach to identifying the causes behind phenomena such as the gender pay gap, the disparity between representation of certain ethnicities within management roles etc, however I'd say the purpose of doing that would be so you actually can "fix" these problems to some extent (and I don't think that's possible without actually understanding the underlying causes).
Btw if anyone is interested in an example of genuine and rational social justice warriors I would point to Heather Heying and Brett Weinstein as great examples, surprisingly enough they actually agree with Peterson in many ways.