What does Marth have over Roy now, besides range?
Marth's aerials got buffed, so he also has faster aerials.
I heard his jab now sends in a completely different angle which allows for true combos but that last part might be speculation (like at the beginning people though Mewtwo's D-Throw true comboed).
Aside from that Marth is still technically more powerful in the sourspot and the sweetspot, his sweetspot is just much harder to land. Plus Marth's gameplay synergizes perfectly with the objective of the game, which is to play effectively.
What I mean is Marth's game is all about being safe and spacing yourself which goes hand in hand with this games engine. Roy is all about being in your opponents face, and his properties help him achieve this but this overall gameplay is not what you want to be doing unless you want to get punished.
Contrary to Melee though, Roy's sourspots are actually good in this game, they deal great damage and are overall decent so Roy can still play a great spacing and safe play without feeling like he is hindered by his gimmick.
Technically Marth will always be trying to land tippers, he will always be playing towards his gimmick. Roy should also be playing towards landing tippers, he should be playing safe looking for an opening to go in and apply pressure, basically playing against his gimmick (until an opportunity arises).
Playing Marth is all about zoning and precision, playing Roy is more about pressure and maximizing opportunities.