... I think the best way to classify a console as Retro is when the manufacture no longer supports the console in everything.
If you got a busted Nintendo 64, you can call the repair line and they'll support you on repairs, however in terms of sending it in to get it fixed, parts and what not; you're better off ordering them from a 3rd party and fixing it yourself.
By-the-by, what do we call SNES, NES and So on when the PS3 and PS4 Goes 'Retro?' Ancient?... I'm joking of course since they already are, though the WiiU, PS3 and Xbox 360 and up still have proper support since they are the most recent since their production lines have halted. When the next generation comes in, those will no longer be supported and it'll be the PS4 and Xbox One X.... Switch is coming up with a Switch PRO, so Nintendo isn't giving up on that baby until they go full VR.
... There's another problem; Gaming has reached it's peak in how we play and interact with it; unless we can simulate entire environments in our bedrooms, living rooms or anything else, there's no other direction for the consoles to go. They'll need to explore new ways to play video games and while Nintendo does that already, Microsoft is sticking with their guns as well as Sony; but they're going to faulter here until another group comes along.
Maybe a WonderSwan revive for the west or a PSP2 with proper L2 and R2 buttons... WHO KNOWS!