Was there ever a solution provided to this question?

I never received an answer and seems not to be available at the moment but i believe would be a good feature for the next set of updates. Would be good to be able to receive notifications based on various events to react quicker to changes and to keep users informed.

Thanks! I just received an unfortunate response from support.

"About your request, I was trying to look for a solution, but in this case, we don't have any specific option that will notify you once a user is added to the account, you can see the records in the Account Audit Logs, but in order to be aware of the new users added to the account, you will have to look for them directly."