For anyone who thinks Neko's announcing Luffy's victory doesn't mean anything, similar scenes with other characters announcing Luffy's victory has happened in the past.
Brûlée announcing that Katakuri lost his fight against Luffy.
Gatz announcing Luffy's victory against Doflamingo
A random Marine announcing that Luffy defeated Rob Lucci.
If Neko's words isn't enough and if the narrator's words isn't enough either, then what more proof do some people want?
It seems like some people forget this is usually how Oda does things, but it seems like some people are so obsessed with their headcanon that they just can't accept that they were wrong.
Other than some delusional extreme Zkk users, I get that for some the ending of the fight felt underwhelming but some of those people will eventually need to face the reality that the fight is officially over.