So would Neon Indian be Chillwave or Vaporwave? Or neither?
I've always associated him with the former.
They were chillwave, but with "VEGA INTL.", I'd say he's gone synthpop, for the better. The best string of songs in 2015 was "Slumlord", "Slumlord's Re-Lease", and "Techno Clique."
And to everyone getting vaporwave confused with synthwave or 80s inspired electronic music, there is a difference. Early vaporwave e.g. in 2012 is focused a lot on slowing songs down and changing the beat behind them to make it seem you're in a haze. Nowadays, the tag is a bit more nebulous with microgenres such as vapor-trap or ambient vaporwave i.e. 2814's album. Future Funk is Vaporwave except the samples are from funk and disco instead of R&B and pop. Basically, vaporwave as it is is a micro-genre in electronic music and anything derivative of it is practically a nano-genre. However, since a lot of albums in the genre use elements from one nano-genre and apply it to another, this classification has gone to hell and back.
TL;DR: Vaporwave -> slowed down and remixed R&B jams and pop what not.
Future funk -> Slowed down and remixed funk and disco
But, this shit doesn't matter because it's all bullshit anyway. Just call it vaporwave and be done with it.