Oddly enough, you’re proving my point. Apple refuses to acknowledge an issue publicly, instead claiming they are “one-offs” that “Engineering needs to investigate.” That can work for hardware, because there really is no real troubleshooting or fixing a customer can do. Where this utterly fails is in software support, with the most recent case being the HomeKit debacle. Apple would prefer to substantially increase the response effort of customers (e.g., come to a store) and quietly pull the update than just publicly say, “We messed-up and will expend our own effort to correct it.”This hasn't been my experience, as someone who has had support issues escalated to engineering (and even had product returns routed to engineering for further investigation).
The inter-team communication is more mailbox-based, so they can't put you on hold and see if anyone on that team is still at the spaceship in Cupertino. Kinda what you would expect for a large international company.
That said, you can hit the end of a script with no escalation. I've seen that a bunch with say battery performance issues, and in those cases I'm sure it was totally on purpose.