We know because we've gone from a16 to a17. The entire way worlds are managed changed, which would require a full wipe of the world. Progression was completely re-worked, so you characters would get wiped. Because the old save data is no longer compatible with the new system.
This alone means that Sony and Microsoft will not allow it. Since TellTale billed the game as complete, they are unable to push an update that would depreciate current save data and force a wipe. If TellTale had properly listed the game as a Alpha port, then this wouldn't be an issue.
That's not even getting into the bits where your console hardware doesn't meet the gameplay specs on newer versions though. Your hardware will struggle greatly to maintain a playable FPS without severe stuttering and freezes. I cover this in detail in the Sitcky.
I see someone on Reddit is quoting you, lol. Two people arguing about the port. Lotta people just don't understand it actually can't run on the hardware. The hardware's the issue, not the game's code. Even after gold optimizations the last gen still wouldn't be able to handle the new engine and stuff. It barely handled previous alphas, and I don't know if I count "25fps on medium graphics with one base" as "handling it."
"Which is kinda pathetic since it is just a Unity game. What are they doing wrong with their code if it can't run on modern gen systems."
"It has nothing to do with their code, it's the hardware itself. It's the same reason why Space Engineers on PC has 16 to 124 player servers, but on Xbox, it's only capable of 2 player co-op, 4 if you use split screen on two Xbox One X's, the souped up version of the console. This also took them 7 years to achieve.
The hardware simply isn't capable of handling an entire dynamic world. It simply doesn't have enough RAM or a CPU to keep up. 8GB is the absolute bare minimum to run this game, on top of that, Microsoft uses an archaic offshoot of FAT32 (2001) for its modern memory in the Xbox, which is a huge reason for all the MD5 errors still present on that system. That file allocation system is just not capable of running 7 Days.
"But CoD runs at 60FPS on Ultra on Xbox!" Yes, and CoD is a game that is 99% static, with the only things being computed are player models moving, and some particle effects from explosions and stuff. Deformation are just scripted animations, like a car exploding and being replaced with a dead car model. (hitscan is hitscan, no projectile calculations like Battlefield)
Games lik 7 Days, SE, are dynamic, real-time, physics calculations, going on, at all times. The game is making sure the entire world is doing what it needs to be doing at any given time, even that dirt block below your feet. It's also not spaghetti code. This ain't no Yandere Simulator if else party."
(This goes on for paragraphs and paragraphs, but at the end they added your quote about saves cause the person was arguing if the dev was competent the saves would work.)