@Calmar:
SpoilerIf yawgmoth survived it's hard to say if Argentium, let alone New Phyrexia would be created since Yawgmoth being alive would mean he won, and thus have taken control of Dominara. If that was the case then Karn would either be destroyed or too pre-occupied with fighting Yawg and his minions to create Argentium so the plane flat out would not exist. Also, with yawg still around the non-black Phyrexians, if they came to exist at all, would either be created BY Yawg and his minions or quickly fall under their control.