Hugo that is quite tricky to implement and honestly, let likely we will be able to give functionality that provides details about all the users that have access to any given post in realtime. The main issue with this type of functionality is that it requires lots of computational power that most definitely will break websites with a large number of users.
For example, in order to determine if the user A has access to "Hello World!" post, AAM has to merge all the access settings as described in this article. Access settings can be overwritten on any level, which makes it not possible to determine with one single query. On top of that, WordPress core does not store information about user roles in a normalized way which, again, complicates things.
As a compromise, we might be able to implement a functionality that generates a report about access to any given resource, however, currently, this is a low priority feature.
Regards,
Vasyl
