I'm still waiting on APV to show up in the Refurbished Products section of the Apple website. I know they probably have plenty but posting them too soon would send a bad message. I will patiently wait.
They may not offer refurbs for the AVP. Some items never make it into the refurb store, depending on what they are. The Pro Display XDR never did, and neither do Hermes Apple Watches. I don't personally think they ever will. The sales are too low and they will most likely keep the returns for replacement parts.