The way that Piccolo initially went from saying they had no idea if Goku was stronger or not to asking what kind of hellish training Galu underwent tells me that he believes he became stronger. Piccolo and Gohan already showed excitement over Goku being able to activate Sign at will.
So to be further impressed after questioning if Goku became stronger should be a pretty clear indicator. Whis congratulating Merus on training Goku so well only backs this notion up. Regardless, given that we learn that the more stable the UI, the more powerful it becomes, that alone should prove that Goku became more powerful. He had far greater control over Sign than at the ToP. His suppressed version being equal to his ToP self is the bare minimum of where he should be.
Also Moro gave Vegeta's power up plenty of praise. Piccolo called him unrecognizable.
Ch. 61, pg. 3.5
Moro: “Yes, you have gained a considerable amount of power. Yet you’re still not able to contend with me.”
Ch. 61, pg. 4.3
Context: Vegeta continues attacking Moro
Piccolo: “Vegeta has gotten stronger. I barely recognize him! But Moro is still more powerful than him. It’s a level that can’t be overcome with training alone…”
Ch. 61, pg. 6.1-4
Moro: “I do commend you for elevating your power to such heights. [ ] You will make for my finest meal yet.”