I would say that rather depends on what OP means by "properly".
If OP already knows Scala and would like to get better at it and one assumes that "Scala as Haskell in the JVM" is more desirable than "Scala as a better Java", then yes, that's a great suggestion.
If OP wants to learn Scala from the ground up, I disagree pretty strongly with starting there. It's a great book, well written, with a wealth of challenging and mind-opening exercises, but I wouldn't recommend that as anyone's first exposure to the language. The second or third, sure, but it purposefully restricts itself to what its authors consider a sane subset of the language.
I happen to agree with their definition, but, in my experience, knowing a programming language is about reading it as well as writing it, and by restricting your learning to a subset of the language, you'll find yourself unable to understand perfectly valid, normal code - code that is part of the standard library, for instance.
I would rather suggest reading Odersky's book while allowing oneself to skip large chunks that go rather in too much details about fairly useless things like the XML API. Or going through scala-exercises (https://www.scala-exercises.org). Or the coursera class - its first incarnation was pretty good, I assume the new one is at least of the same caliber. They might not make you an expert overnight, but they'll get you to know most of the Scala features you're likely to encounter in the wild, and to be able to read and learn from most Scala OSS projects.
I actually learned Scala from this book, and the only languages I had used in production before were Python and Fortran. I don't think learning the functional subset first made it harder for me to learn the object-oriented and imperative parts later on. Plus, understanding the functional subset gives you a better understanding of many of the internals, such as what `for` comprehensions are actually doing.
Of course, if you just read one book and stop there, I'd agree. But most people will continue learning from tutorials, videos, stackoverflow, etc.
I've also seen several other people learn Scala this way, usually without knowing any functional programming before, and really haven't seen any signs of issues wrt not understanding code written in other styles.
That book is by far the best one I ever read about Functional Programming in general, even if you don't want to learn Scala itself it is an amazing reading about FP.
