I haven't read any of the novels and comics from the Disney era, but my understanding is that, also in the new continuity, almost a year passes between Empire and Return, during which Luke carried on several important missions for the Alliance.Is he, though? Yeah, he's famous as the guy who took the shot that destroyed the first Death Star. But everything that happened after that, everything that was related to him being a powerful Jedi, happened somewhat behind the scenes, known only to his friends at most. He trained on a planet so obscure that Yoda successfully hid out there for twenty years, he made a brief visit to a gas mine on Bespin and basically hardly met anyone, then he broke his friend out from Jabba's palace in a fashion that pretty much left no living witnesses, before going on what was already a covert mission, splitting off from that mission and going to confront Vader and the Emperor alone, an act in which, again, there were pretty much no surviving witnesses.
Most of the galaxy probably doesn't even know he was there, they assume that Vader and Palpatine died when the second Death Star exploded. Unless Luke went out of his way to make his part in those events widely known, there's no reason why they would be.
He doesn't strike me as particularly shy about his Jedi connections: he carries his lightsaber openly in the movies, and C3PO told the Ewoks of the fight with Vader on Bespin. The Rebellion has at least a superficial faith in the Force; having a Jedi on their side would be a huge morale boost, so I don't see Luke being particularly secretive about his powers.
I expect very few people knew he was Vader's son, but it's not unreasonable to think that most Rebels knew there was a Jedi in their midst, even if they may have not been able to recognize him if they actually met.