I believe that was the point. Soft delete isn't a product requirement, it's an implementation detail, so product teams should talk about the user experience using language like "delete" or "archive" or "undo" or "customer support retrieves deleted data".

Yeah: You don't "delete" a bank account, you close it, and you don't "undo", you reopen it, etc. The processes have conditions, audit rules, attached information, side-effects, etc. In some cases the same entity can't be restored, and you have to instead create a successor.

"Undo" may work as shorthand for "whatever the best reversing actions happen to be", but as any system grows it stops being simple.

Sure. Did someone say that the behavior should be described to customers as soft delete, though?

I read a blog about a technical topic aimed at engineers, not customers.