I tried to think of a well done argument to this that SSB4's NAir is fine.
But honestly it's mostly good tradeoffs with Brawl NAir. SSB4's NAir has larger side multihit hitboxes, at least.
That said I firmly believe Sakurai will not do retrogressive designs for patches and go back to Brawl designs intentionally. We need to accept this fact better (I mean this at lots of Zeldas.) That's why we need to say goodbye to Brawl's Zelda everything.
It's not like these patches haven't made some of our moves arguably better, or brought them closer to new utilities. Jab in particular is 90% better than Brawl's Jab, and UAir never had sub 20 frame landing lag. (Albiet 19 frames...)
Also you DON'T want Melee NAir data. On the outside it looks fine, but it was a shameful and terrible move with tiny hitboxes and it never connected. Besides that landing lag is only 1 frame better. Sure its FAF was good but that was pretty much it.
I am also annoyed how every smash game reduces the number of hits her multihit attacks do. Nayru's from Melee > Brawl > Smash 4 went 6 > 5 > 4 in hits, and NAir lost one hit (And subsequently some of its hit duration) when brought to Brawl. Usmash went from 12 > 11 > 8. That bothers me less tbh because th hits are still spread over roughly the same length, so there wasn't a real duration loss.
Can you imagine if NAir still did do 6 hits, but the only change was 1 more multi hit? That would be pretty neat. Damage would be 8/13%, it would release opponents later our of SH NAir possible allowing more different followups, it would cover her longer too.