>  Can anybody share an API endpoint where we can request this list of "deleted" accounts?

Just FYI, there's no need for an API endpoint to do this.  Accounts like this are basically hard-coded into the front-end.  If a front-end wanted to share its list to other front-ends, then maybe it might make sense to create an API method.  But for the moment, each front-end just manages their lists independently.

In the case of condenser, you can just take a peek at:

[GDPRUserList.js](https://github.com/steemit/condenser/blob/master/src/app/utils/GDPRUserList.js)