Variaudio bounce: "Create Part from Region?" dialogue

Hi - Does anyone else get this message when they bounce their final comp? I have been seeing this when I have put a previous comp in a part, then recorded another take ( as in here, the relevant part is the bit in red: ) .

There’s no help button with the dialog, and I couldn’t find this message in the manual. I don’t use regions much (cough …), so I’m not really sure what all that means.

Thanks for any help!