Nope. Not unless ASRock managed to get a Ryzen CPU to run on a 780G/760G mobo.
(They've done Hybrid-type mobos in the past, but I think that perhaps even that might be beyond them. Besides, what would be the point of it?)
Pardon me but isn't this still common on servers?you are reading it wrong.
onboard video support just means it has the video outputs (dvi,hdmi,dp) needed for an apu to be able to pass thru the frame buffer contents. in no circumstance does it mean the board has a gpu built in. that sort of chipset igp hasnt been common for over a decade.