They already tried this and it failed many times. What I mean, is they already tried new upgraded versions, like sega 32x or sega cd, and you cannot split your console market and still succeed.
The whole point of consoles is that it is one hardware, and all games are optimised to take advantage of that. I really don't see why Sony and MS would want to release version 1.1 with faster hardware. That doesn't make any sense. Leaving all the early adopters behind? They could easily do that right now, but for the reasons I said, that is not something they would even consider or want.
In that case, most of us won't bother buying the system knowing a better one is just right around the corner. Just doesn't make any sense really.
And with my experience with PS now, latency issues weren't resolved, and unless they can somehow bend space and time to I can't imagine it will ever get better. Even now you need to hardwire your PS4 to your router, because going wireless is not an option, yet that is how most people will need to play it.
People like and want a dedicated console, with physical games. As long as the games are there, they are not too fussed by better hardware coming onto the scene. If that was at all possible, PC gaming would've taken over long long ago. But, nope, console gamers haven't flocked to PCs because of their aging consoles, kinda strange to suggest improving hardware is a driver of this.
These are not the last consoles.