Yes, next-gen we will see games use less vram because of course that makes sense. That's why consoles launch with less vram than before. 
https://nevalalee.wordpress.com/2011/08/09/blinns-law-and-the-paradox-of-efficiency/

https://nevalalee.wordpress.com/2011/08/09/blinns-law-and-the-paradox-of-efficiency/