is the minimum spec for Odyssey around the ps4/XB territory or way out?
For a first party developer, for either console, it'd be probably more than possible. I am not sure about the Xbox games but we had some absolutely strikingly good looking games on the PS4... by the first party devs. So it can be done. All that spiel about how "galaxy 1:1 and bla bla" is just thrown around by people who think this is an unimaginable project which takes a few Cray supercomputers to run. No, it doesn't need that, it's just lazy, bad or incompetent optimization. Everyone will choose the easiest way out when developing, least money and man-hours involved, the better.
For a third party, like FDEV... I am not sure they will have the teams and money to make it work good enough. If the last gen versions aren't dropped altogether, I am expecting a pretty bad version on PS4/Xbox One/X. Best case scenario, it will run probably just as Horizons runs now on previous gen, worst case, it'll run slightly worse, dumbed down graphics and frame rate.
While I really hope they will not drop previous gen support (there's a huge market for that still), I would love an actual gen version of EDH/EDO. Many of the MMO games (of which variety Elite Dangerous belongs... in some way) bring actual generation optimizations, ESO, Destiny 2, Warframe, NMS, to name some higher profile games. We might see something like that coming from FDEV, who knows.
Really interested to see if that roadmap of theirs will list only fixes for the PC, or does it also include some console love as well?