For me, if you type:

    when you do `foo()` it foos the bar.

It does the right thing for me. This was the case yesterday and it still is today.

It's possible that the author got a different release. It's also possible that the author was trying other very similar scenarios that behave differently, e.g. backquotes behaves differently at word boundaries and inside a span that has already been converted to the code-formatted rendering.

Overall it's pretty confusing, but the simple case that the original article points out works fine.