Um RAM doesn't really work that way. Well it could, but it won't.

Games have 5GB. Other things have 2.5 GB. HV has .5 GB. Just because "Other things" may not be using all its ram, the game will not expand into it. Does anyone expect to be playing Halo 5 and have the message come up "For better graphics and game performance, please close your open apps"? No lol.

why not....

but even then you don't need to close anything it is suspended..... it won't take up much ram in suspended state.... and I can hardly imagine a snaped app use up that much RAM

it's perfectly doable and a workable.... they can target 5 for their game and add extra stuff that require more to look better on an availability basis.... it's not like the amplitude of ram use from apps while gaming will fluctuate much.... this isn't a PC

and once again.... they are not their yet.... before they max out 5 the OS footprint will have shrinked more than likely

Debating the technical aspects of this is useless. Obviously all that really matters is that it works flawlessly from the users end. Like others have said, it will be more optimized over time and with games released later, maybe M$ will allow 6gb or whatever anyway.

I think they just played safe at first and optimized especially for speed. Especially given that they implement such a complex system with 3 "kernels" shows they put a lot effort in their way of os-implementation and I doubt they fail in this category. They didn't with first Xbox, they didn't with 360 (still can't believe the ridiculous low 32mb...) and they won't with Xbone.

Because MS said so themselves? Try to read and understand what MS wrote about the various states software can be in on the XBox One.

I agree, it's most probable that both the PS4 and the XOne will allow developers to use 6gb+ at some point.  And when they do, it will probably be needed by the developers.

From what we know, the xbox one does not suspend apps even when they are no on screen.

As for your second paragraph, this isn't a PC. That's not how things work and how devs want to code. Also its flat out absurd to the consumer as I showed with my Halo 5 message.

Your last line is correct. What does that have to do with a non static ram allocation?