If he was more powerful than before at base, no one said anything about it... So I tend to think his base didn't change much.
*And just so everyone is on the same page: the "Mystic" amp was not part of Gohan's true 'base' power, even back with the original material was first written. It was treated as a transformation of sorts that he had to consciously activate -- it just stacked on top of his base power:
https://i.imgur.com/Dy10Kw2.jpg
https://i.imgur.com/UIrKX5Z.jpg
https://i.imgur.com/XT9S7F7.jpg
https://i.imgur.com/kYmWg11.jpg
Gohan: "How do I become this ultimate fighter?!"
Old Kai: "You turn into that Super whatever often enough... Fire it up, just like that!"
