All I would say is that I didn't appreciate its reveal. Not enough meat on the bones

No, it will just be in limbo for half a decade and will then resurface as Final Fantasy 16 and will be released another half of a decade later.

Forget Deep Down, just look at SE's own tech demos that never really turned into anything as an example of them showing things that never really turn into what you're thinking. 2012 tech demo: Agni's Philosophy

It's a tech demo. It was never meant to be game. Project Athia is a game. Project Athia has been in development since SE cancelled the last of FFXV's DLCs. This thread has absolutely no basis to exist.

By the way, What were the other gens vapourware?

uhm.. tech demos only exist to show off tech, they usually aren't ment to turn into anything - Kara turning into Detroit is a very rare case

True. Maybe the term is a little too hard to lean on. That said, there was so little to Athia that I wouldn't really call what we saw a game. I didn't really push for more info, but I recall VS XIII being something that was shown off a lot before scrapped and (if Im not mistaken) taken to make XV, which is what came to mind as another showcase that really didn't happen.

PS4 - Deep Down

PS3 - Ni-Oh (2004), The Last Guardian (2009), FF Versus XIII aka FFXV (2006)

PS2/Xbox/GC - Starcraft: Ghost (2002)

PS1 - Too Human (1999)
N64 - Mother 3

Duke Nukem Forever, Team Fortress 2,  Half-Life 2 Episode 3, are all classic PC examples.

Key words "and nerver come out" 

I'm pretty sure Ni-OH, The Last Guardian, FFXV(Im positive I have a plat on this one), Too Human, Mother 3, DNF all came out. 

When i first saw the trailer this was exactly what I thought.

I see. FIXED.

The console games I listed originally never released on the platforms they were originally announced for though. Those versions are vaporware.