Yes, they are. But contrary to what you might think it should be *very rare* that this turns out to be a problem.
If you ever find yourself thinking that you need a solution like the one presented in the article, you should stop for a moment and think again.
There's *almost surely* a better way to write your code and make it better than having to check if "this is an object and it is not null but it is empty". This code...
if (typeof value === 'object' && value != null && Object.keys(value).length == 0)
...is not good code.