Spider-Man Miles Morales, Horizon Forbidden West and Sackboy are cross-gen games
This means that they have also been developed for PS4, and will arrive on the current generation console at the same time as their launch on PS5.
Sony justified this by stating that it also wanted to make the large number of PS4 audiences enjoy these titles, a statement that is jarring with previous announcements in which the Japanese company stated that it "believes in the generations" and that it wants to create the new games solely for the new hardware, even going so far as to explicitly declare Ghost of Tsushima would be the last game produced for PS4.
On the practical front, Sony explained that the digital version of these titles will be automatically upgraded to the PS5 version when you play it on the new console, and the same will happen with the one on disk, but it will only be playable on the most expensive version, and equipped with an optical player, of the console. An interesting note is also related to the disc versions of these games: ps4 discs are playable on PS5 but not the other way around, so in general if you think you want to play titles on both consoles, it is better to buy them in PS4 version.