>Is amazon going to tell me that up front? In the restaurant case the manager can explain [...]

In either case they can explain, it's entirely orthogonal to the question of whether it's in-person or not. There's no technical reason why Amazon can't send you a email saying that you were banned for excessive returns, for instance. Moreover I can imagine plenty of reasons why a restaurant manager might not want to explain the precise reason, such as the threat of lawsuits, or not wanting to create an argument/scene. See also, why some HR/hiring managers are cagey about why you were turned down for a job.

>The difference between the analog word and the digital word is extreme.

The difference between a hyper-connected metropolises of today, and a random village in the 1800s is also extreme.