There's a couple bits of that description that I find interesting, in this context:

The clinical features most commonly associated with aboulia are:[5]
...
* Reduced emotional responsiveness and spontaneity

As opposed to 'lack of emotional responsiveness' or 'lack of emotions' - in other words, I suspect that the people in question are experiencing emotions, but don't feel any drive to communicate that fact.

Most experts agreed that aboulia is clinically distinct from depression, akinetic mutism, and alexithymia.

This is less clear, but again it reads to me as saying that aboulia is not related to a lack of emotions or emotional awareness. I also note that anhedonia isn't mentioned at all in relation to it.