Take this for what it’s worth, as I really don’t have a definitive answer.
I noticed as I was walking through OP one morning that there was a couple sitting at a table in the coffee area eating scrambled eggs etc. It caught me by surprise as I couldn’t figure where they got it. Although a possibility, I would find it odd for them to have brought it down from the Lido buffet. As such, I believe there is a possibility that they do in fact have a small buffet area set up in OP. I personally wasn’t interested in eating there, so I didn’t investigate further.
This was on the Aug 5-12 Vista sailing.