It can and should be assumed that Hyne (asuming Hyne was a real figure and not a mythological device) passed the Witch Embodiment on to Edea, but only in the sense that Hyne was the progenitor of the Embodiment. Edea's powers were explicitly received from Ultimecia, meaning that any Sorceresses preceding Edea were and are irrelevant to her power.
Actually, Edea explicitly states that she was already a sorceress BEFORE Ultimecia gives her her powers, hence your conclusion that any sorceresses preceding Edea are irrelevant is incorrect. There was a sorceress before Edea (certainly not Hyne by the way) whom Edea received powers from. Ultimecia simply gave Edea even more powers. Clearly though, we cannot ignore the impact of the first sorceress!