It is reproducible. It has to be for their feature to work. They're trying to find some way to communicate to people that the recording is to a ring buffer, and isn't durably saving everything it hears indefinitely. It's an unenviable position to have to find a way to sell your engineering that enables a fairly privacy-preserving implementation of a feature that intuitively feels like it depends on surveillance to a mass audience. Made especially difficult by the environment where most products really are surveilling you even when they don't need to.

Of course, Apple still collects more data than it needs to and abuses users in other ways, so I don't really feel bad for them.

Would you consider a phone call / VoIP a recording? Your voice is being encoded into digital data and put in a small buffer before it can be transmitted to the recipient.

Don't mean to make this sound like a gotcha, but the technical implementation is secondary to how there's no output .wav anyone could play back. I think saying "there's no recording" is a fair and clear to normal people description of what happens.