This isn't particularly scalable for T-Mobile and I'd say they haven't done themselves or their customers any favours. The customer service experience should be the same regardless of whether you go in from the top or the bottom. If a customer has a better experience by going in from the top, I think that just implies that the customer service frontlines are failing.

It's good that the CEO is so accessible, but no reasonable customer should need to reach out to the CEO in order to get the a good CS experience.