I don't think we can alter the distribution list for those emails. Lets hear what others have to say.
However, I would like to highlight one point. These emails are actually related to Participants in the team. That is, these emails will be triggered when a participant is added/removed from a project. I guess your Project Management settings in Clarity are set such that every resource added as staff becomes a participant. Hence, whenever you add a resource to team, email is triggered. But when you remove resource from staff, you do not get email because the resource still exists as participant. Remove the resource as participant , then you should get an email.