Yes but how would he get there? Fishman Island wouldn't be discovered for 200 years, that means coating wasn't a thing yet (if not someone else would have seen fishman island and it would be a common knowledge place by this point), Noland's a botanist not a coating engineer so he wouldn't have known what to do. And if somehow he had gotten there he would have left some mark, that's something Oda has always been very good about: he made it clear that Roger had visited Skypiea, made sure we knew Noland went to Dressrosa, confirmed that sky people at some point lived on the moon. Oda knows what he's doing if he had sent Noland through fishman island he would have told us so in the arc where fishman island and its history took the center stage
I thought it was that it wasn't until 200 years ago that the Fishmen were considered as more than fish by the world government. The existence of fishmen has been know for more than that. Seeing as Norland wasn't a pirate it could have been either way though.
Fishman Island had been known to exist there since the void century, and we don't know how long ship coating with the bubbles has existed. So either way all we know is that he did in fact make it to the new world.
We also know that Roger did go through the Fishman Island route, but he didn't actually leave anything like when he did in Sky Island.