Yes, it is intentional. The functionality actually exists, it's just not mentioned:

https://github.com/skorokithakis/expounder/blob/master/examp...

It's because, once clicked, the new text should become part of the old, and that's it. Presumably you've already read it, and I don't want to make the viewer have to re-collapse the links every time.

Your use case makes sense, though, which is why the feature was included. Maybe I should mention it in the README.