Howdy ravendatatech,
That does sound very possible. It would not even require any knowledge of our API. Events are 100% WP Post Types. You would rely purely on WordPress for that. You could tap into WP actions that indicate an even has been published, then email a list of WP users to a specified address.
The above would obviously require a fair amount of coding though. You might be able to make the listing of uisers a bit easier by using a plugin like this: https://wordpress.org/plugins/list-users-emails/
I do not know of a simpler way 🙁 . Is there something you are trying to accomplish that would be of use to other Events Calendar users? If so, why not suggest it as a feature?
Let me know if that answers your question, or if I can answer anything else. Thanks!
– Brook