Thats pretty bunk. The entire climax was very clearly framed as Luffy running out of energy, and needing the support of Gatz and all the others to make it through. Luffy was about to pass out when Gatz reached him, he could barely even stand.
And on the flip side, saying that "Luffy would've won either way" just makes the effort of Gatz and everyone else to delay Doflamingo seem completely pointless.
Theres a lot of questionable things regarding the handling of Haki, but putting it on a timer takes the cake.
So what Oda is saying, is Caesar is totally joining the crew, right?
Seriously, while I appreciate Oda pointing out the (extremely) obvious here, it also throws the Straw Hat behavior in the Whole Cake ark in even worse light. Because while Nami apparently think Caesar is rotten to the core, with explicit backup from the author…that sure didn't make her raise any objections to using Caesars horrible weaponry to kill Big Mom. Nobody seemed to have any problem with that.
The translation was done by another person and it said
Q: I read the manga and watched the anime and noticed that after Luffy uses Gear 4, he not only can’t use Haki for 10 minutes but it also carries the tradeoff (risk) of being so fatigued that he can’t move. However, in Ch 885 he is moving totally normally right? Why isn't that tradeoff there anymore? P.N. BUSHI
Oda: The tradeoff of not being able to move that you’re referring to never existed in the first place. If he wanted to move but couldn’t use Haki during that time, he could still run from place to place to hide. In Dressrosa, after using Gear 4, he coincidentally ran into his allies and supporters so he could preserve his energy while they carried him to the next fight. If those people weren’t there then Luffy would just have to do his best!
This translation especially the last one makes far more sense as to how oda responds as he's stated pretty early on he never likes to comment on who would win in a fight between two peopl.
But I agree with you the standard growth of him leading him to move around more made enough sense of its own. Maybe doffy would beaten him up a bit more and he'd still win but the damage would be a lot worse. I mean we saw luffy take a ton of attacks from katakuri anyways