Oh, well I think what he meant is that some malicious program could read and transmit this unencrypted recorded data which is normally stored in an encrypted form
Thanks, I think so too, but the threat model is a bit odd. On a Mac, potentially malicious programs do not normally have access to files in every location (e.g. the prompts to allow a process to access your Documents dir); there is hardware-backed crypto available for further protections; full disk encryption; and so on. It's unclear to me how to evaluate the severity of the risk.
Every security decision is a risk-reward tradeoff, and the reward of a complete memory of computing tasks seems pretty huge.