No. Whosoever sees the essence of God does not know all things because all things are seen in God as an effect is seen in its cause.
An intellect can know all the effects of a cause and the reasons for those effects in the cause itself, if it comprehends the cause wholly. But no created intellect can comprehend God wholly.
Therefore no created intellect in seeing God can know all that God does or can do, for this would be to comprehend His power wholly. Yet any intellect can know more of what God does or can do if it sees God more perfectly.