Let's talk about this.
For example, when will the nostalgia wave hit Haruhi? Ten years, maybe, since the anime was made about ten years after Eva, and now Eva is now in full nostalgia mode. Sailor Moon hit and we got Sailor Moon Crystal pretty early. Mahoujin Guru Guru and Komugi-chan both got new anime, so it's safe to say the wave is somewhere in the 90's now.
It might take a big longer for it to happen in Japan because they aren't marketing to Nostalgia as much as the west, but now that Netflix has their hand in anime, they might push it forward a bit.
I also think there's a second, smaller wave that just hits select classic 60's-70's shows like Dororo, Devilman, and Time Bokan. Do you think Zambot 3 or Umi no Triton will ever get a remake? There's a new Saint Seiya out, but maybe Yuu Yuu Hakusho will get the Netflix treatment next. What do you think?
If Gainax ever gets their shit together, they can capitalize on this with Top wo Nerae 3 and their Zero Centure Leiji Mastomoto films, but I'm not holding my breath for that. Anno needs to get 4.0 out already.
Searching for "懐かしいアニメ" gave me the following images. Make of this what you will.