What’s more likely, an Amazon owned company blocking Israeli accounts on moral/ethical grounds or some backend technical reason? My guess is the latter…
Or one employee being an activist and sneaking in a config change.
If we’re getting specific, a botnet in the region creating accounts might trigger a precautionary lock down like this.
Up until recently support responded to tickets of people asking why they couldn't sign up telling them they were forbidden to join. So it was at least semi-official and allowed as a reason for closing support tickets.