Something which was once a statement and started with a keyword can become an expression in a new version of a language.

For example, in C# 7, throws were made into expressions to allow syntax like this:

  return a ? b : throw new Exception();

So I wouldn't rely on this rule.

Ouch! I like to rely on the ternary operator as a cheat for if/then just as much as the next guy, but that qualifies as abuse, lol!

I wouldn't say that's abuse and I missed that many many times in JS/TS, for example on unreachable variants in tagged enums. This usually turns into null with a null check afterwards just to throw the exception, which is more verbose for no reason.