Your comments are very confusing.

> For someone who's used to seeing "&" as an "address of" operator (or, a pointer)

You must be talking about "&something" which takes the "address of something" but the OP does not talk about this at all. You know this because you wrote in your other comment ...

> And if this indeed the case, why is int&& x compatible with int& y ?

So you clearly understand the OP is discussing "int&&" and "int&". Those are totally different from "&something". Even a cursory reading of the OP should tell you these are references, not the "address of something" that you're probably more familiar with.

One is rvalue reference and the other is lvalue reference and I agree that the article could have explained it better what they mean. But the OP doesn't seem to be an introductory piece. It's clearly aimed at intermediate to advanced C++ developers. What I find confusing is that you're mixing up something specific like "int&&" with "&something", which are entirely different concepts.

I mean when have you ever seen "int&" to be "address of" or "pointer"? You have only seen "&something" and "int*" and "int**" be "address of" or "pointer", haven't you?