You are neglecting a third possibility in that it was accidentally generated in lab conditions. The furin cleavage site is a large insert relative to its closes

You are neglecting a third possibility in that it was accidentally generated in lab conditions. The furin cleavage site is a large insert relative to its closest aligning viral genome and is consistent with adaptation to cell culture conditions. The situation would look like someone infecting cells in a dish with some starter virus and continually passaging the supernatant to cells in new dishes, to examine the evolutionary adaptations. This person could have accidentally synthesized SARS-COV-2, and using improper safety protocols, got it on themselves and then went out and infected someone else.