No nothing has changed luffys fruit was garbage that he polished it being a mythicalgod fruit doesn't change that it didn't give him anything special before he awakened the fruit and he had to train his ass off before that happened
Luffy awakening just gives him a unique heartbeat. And joy boy also awakened it so he had that same heartbeat which is what zunisha heard he wasnt take. Over by joyboy its just a title
The reads like a frantic defense, as it is. Oda would like it both ways but it can't be: achieving with a low ceiling is invalidated by a retroactively high ceiling. He wasn't using a bad power to its potential and if anything he was about on par.
If Kizaru believed he has a flash power, then kicked everyone's ass and found out that it is actually the totality of light (speed, density/intangibility, and heat) then he wouldn't retain that initial credit. Luffy's strength and endurance being enhanced is a very direct result of being a Zoan. To boot the power unconsciously awakened after he fell short (let's not forget a hideous contrast to Kaido in that) and the unconscious rhythm summons one literal deus ex machina after another.
He went from a character in defiance of doubt to a character who is credited for traits to which he's oblivious. When he's wrong the world will bend itself backwards to make him right, and so really he doesn't need to work as hard or learn the lessons he should. He's nothing more than a slave of destiny, just happens to be a favored one.