Look, I hate this proposal from Google as much as anyone else here, but let’s stick to the facts.
As the “assembly” part indicates, it’s intended to be as hard to analyze
The “assembly” is just a reference to machine instructions, a.k.a “assembly language”.
Minified javascript, on the other hand, is made with the express purpose of obfuscation and as well, minimize load times, but mainly obfuscation in practice.
That’s to say, you don’t need webassembly to make it hard to reverse engineer. At least webassembly is a standard.
First there was Java, then there was Flash, now there is Webassembly
First, there were machine instruction, then people invented handy mnemonics for those and called “assembly language”. Then there was C, then C++ (let’s skip the basic, pascal, etc) and those weren’t meant to be hard to analyze, they were and still are meant to be close to the machine, to be fast. Webassembly has similar goals. They can be relatively easily decompiled, just as much as webassembly I’m sure, unless they are purposefully obfuscated.
Just like native machine code and javascript, it can be decompiled/reverse engineered, and also obfuscated, but that’s not its goal, not as stated nor in practice.