They're good points from both of you. As a pilot there's a subtle difference to being cleared to do xyz inside CTA, compared to more or less freely wandering around in CTA. That's the important difference (to us) about requesting a clearance or establishing communications.
There's also the subtle & important difference that FWA-NATCA highlighted about what is considered to meet the 'establish comms' rule ie a response with your callsign or a general call (even though it's directed at you).