UPDATE: Publisher Private Division provided an update on Twitter that clarifies how The Outer Worlds will run on both Xbox One X and PS4 Pro. Here is the tweet in full; original article follows.
The @OuterWorlds is enhanced for both Xbox One X and PS4 Pro. It includes 4K textures and resolution on Xbox One X and PC, and upsamples to 4K from 1440p on PS4 Pro. It looks great across all platforms and we’re excited for players to experience The Outer Worlds on October 25th.— Private Division (@PrivateDivision) October 16, 2019
Apparently, the Xbox One X version of The Outer Worlds is the only one which will be receiving graphical enhancements, despite the availability of Sony's PlayStation 4 Pro. Scheduled for release later this month, Obsidian Entertainment's upcoming science fiction RPG is billed as a spiritual successor to Fallout: New Vegas and will also be available to players who participate in the Xbox Game Pass program.
The Outer Worlds is one of Screen Rant's most anticipated games of 2019, thanks in part to the developer's pedigree in crafting extensive, lived-in worlds filled with memorable characters and engrossing quest lines. Featuring a return of New Vegas' Survival Mode, faction reputations, and a complete lack of crafting, The Outer Worlds will see players exploring a corporation-owned star system complete with all the satire and black humor fans have come to expect from the original Fallout and recent South Park developers.
However, it appears not all versions of the game will look exactly the same. As reported by Windows Central, The Outer Worlds will only be getting graphical enhancements on the Xbox One X. According to a spokesperson for the game's publisher, Private Division, the game will be displayed at 4K resolution on the Xbox One but "no enhancements for PS4 Pro" will be available upon release. This is somewhat uncommon, as most AAA games these days deliver enhanced versions for both consoles if at all possible.
Although no official reason for this determination is given, one possible explanation could be that Microsoft purchased Obsidian Entertainment, along with developers inXile Entertainment, late last year, and although the company previously stated they would not interfere with any ongoing projects with regards to releasing in-progress titles on other consoles, it would definitely be in their best interest to make sure the most impressive version of The Outer Worlds is available on their console only. In the past, Corporate Vice President of Xbox Game Studios Matt Booty also indicated any sequels to The Outer Worlds could possibly be Xbox-exclusive titles, giving this theory even more credence.
Whatever the reason, it's always disappointing when players don't receive the same experience across all consoles. Although hopefully the graphical difference between the Xbox One X and the PlayStation 4 versions of The Outer Worlds isn't drastic enough to warrant much player irritability, just knowing there is a better looking version out there is enough to make some people think twice when deciding which console's library is getting added to, a thought process that may indeed be what Microsoft is hoping for.
Source: Windows Central