Any incompletely applied delete will have the chance of be present in the reads. There is no notion of a quorum in the game. A single replica that didn't receive the delete will be able to mix-in its not-yet-deleted element.

(I see many readers wondering here why we implemented it that way. Perhaps a short justification is in order... along the lines: "In that way, we avoid reading from the remove set for every read, effectively halving the cost of the read queries.")