Rambam, Mishneh Torah 3:8:
“Three individuals are described as Epicursim:
a) one who denies the existence of prophecy and maintains that there is no knowledge communicated from God to the hearts of men;
b) one who disputes the prophecy of Moses, our teacher;’
c) one who maintains that the Creator is not aware of the deeds of men.”
Nothing about disputing Chazal there.