A big reason for that is it comes from the CEO. Other providers have a team and then at least 2 to 3 layers of management above them and a dotted line legal counsel. So the goal posts randomly shift from "more information" to "no information" over time based on the relationships of that entire chain, the customer heat of the moment, and personality.

Underneath a public statement they all have extremely detailed post-mortems. But how much goes public is 100% random from the customer's perspective. There's no Monday Morning QB'ing the CEO, but there absolutely is "Day-Shift SRE Leader Phil"