Nah, ZUN will not allow it. He want to Touhou to stay as a doujin franchise.
Besides, the fans already made the anime themselves.
>Zun knows Aniki
I'm more jealous of that fact than anything else he's ever done.
Only if it's animated by ZUN
I don't think it was copywrite so much as they had no intentions of showing it anywhere else. ZUN gave his permission for this, but since it's linked to a anime store chain and produced by a big name studio (Ufotable) it was probably just allowed as a one time thing. Who knows if they even saved the original copies from the showing.