I’m skeptical too.
Lots of software is designed so the delete button just flags an entry so it doesn’t show to low privilege users on the front end, while the data persists in the database where database admins and the like can still access it.
Online it’s wise to assume every website acts like this if you don’t actually run the site yourself with full admin access to the underlying web server and database . Once what you write gets on a site it is permanently out of your control in most cases.
Dungeons and (bad) Dragons