Horizon Forbidden West was supposed to have a free upgrade from PS4 to PS5

Sony announced Thursday that Horizon Forbidden West, the sequel to Horizon Zero Dawn's Horizon Zero Dawn game, will be available for pre-order before its February 2022 release. Contrary to what Sony stated last year (h/t Forbes), the game will not be available for upgrade from PlayStation 4 or PlayStation 5.
Sony announced that Horizon Forbidden West would receive a free upgrade to the PS4 version from the PS4 version in a September 2020 blog post:

We also know that different times will be elapsed for the PS4 community to transition to PS5 and we are happy to announce PS4 versions some of our exclusives. The PS4 will also be the launch platform for Marvels Spider-Man Miles Morales and Sackboy A Big Adventure as well as Horizon Forbidden West. These three games are designed to make use of PS5's unique next-gen features, such as the dualSense controller and ultra-high-speed SSD. PS4 owners can also enjoy these experiences once they launch. Both the PS4 digital and PS4 disc versions include free upgrades on both PS5 consoles. The PS4 disc versions include an upgrade on the PS5 with Ultra HD Blue-Ray disc drive.

As Polygon notes, Jim Ryan, chief executive at Sony Interactive Entertainment, said last year to the Washington Posts Launcher section that games for PS5 would have been built from scratch. The company also offered a free upgrade path for PS4 owners so they could get the PS5 versions.

Ryan stated to the Post that nobody should be disappointed and that it was about people choosing.

Sony's announcement this week was...not that. If you want to play Horizon Forbidden West on PS4, then you will need to purchase the digital copies. These packages cost $79.99 for Digital Deluxe edition, $199.99 Collectors edition and $259.99 Regalla edition. You can also get the standard PS4 edition for $59.99, and later purchase a new PS5 copy at a full price of $69.99. According to Horizon Forbidden West's support page, there is no plan for an upgrade.

We reached out to Sony to get clarification on why they have changed their previously announced plans to offer a free upgrade from Horizon Forbidden West to PS4 versions. We will update you if we hear back.