Discussing the CAP theorem is a discussion on what is theoretically possible.
All I am claiming is that it is theoretically possible to make a CP system that, in practice, is highly available. That does not mean one actually exists.
Absolutely agreed; I'm just saying that as the Pagerduty postmortem demonstrates, CP availability becomes trickier as you increase the number of sites--and there are unavoidable minimum latency bounds due to the speed of light. Those bounds may be unacceptably high; this is why Google Spanner chooses instead to enforce strong bounds on clock synchronization.
All I am claiming is that it is theoretically possible to make a CP system that, in practice, is highly available. That does not mean one actually exists.