With all due respect, being a Sporting man myself and siding with your long term vision that William has tremendous potential, his passing is nowhere near Fàbregas. Cesc Fàbregas is one of the best passers in world football, incisive, accurate and with a tremendous vision, especially in the final third. William is a solid passer, but he keeps it simple most of the time. Good long and short range passer, but again, not even close to Fàbregas. I'd compare him to Busquets in that aspect of his game.
Pretty sure he was talking about Joao Mario.
Anyway, William's passing is as good as Busquets? Not sure about that, but I've only seen him 5 or 6 times tbh (and I do rate him very highly).