Xbox Series X is forward compatible, A series X disc could play on all the Xbox One consoles...
Well...not really. MS titles will be last gen and simply ported to Series X, as in....they will be XONE games that can play on Series X...... That is based on MICROSOFT choosing to do that, that isn't something you are going to see all 3rd party developers do to even argue that is the systems feature or something.
It would be like saying PS3 is forwards compatible and FFVII port on PSN can play the regular disk from PS1...... or, or....they simply play both versions. The PSN port and the PS1 original.
So from what I'm reading about what MS is doing, they are going to continue to support XONE, so if Hellblade 2 is getting bump in resolution because of Series X, I see that NO DIFFERENT then it getting a bump from XBONE X, its simply a XONE game that is getting a bump in resolution and frame rate. To me, that isn't "forwards compatible", that is simply not releasing next gen games and just continue to make XONE games.
Could we not call XB Series X, the NEXT upgrade for XONE X? Lets just argue for a minute that MS and Sony said they want a upgrade to this gen like X and Pro, and MS's first upgrade was the XBONE SERIES X aka XBONE X2 or something, would it not actually be EXACTLY what you are even talking about?
A XONE game that plays on XONE X is a moot point, we know that is what its going to do as it was made to just play XONE games better, Series X pretty much sounds exactly like that if they have no interest int he next 2 years to make any new games for Series X.
Might as well say it is a X2 or something. Putting a "Series X" on the box doesn't change anything anymore then putting XONE on the box of 360 games would change something and when they added BC, they did that too btw.
So no fancy names needed, its simply a last gen game playing on a current gen system.