The upcoming racing sim won’t be releasing on the PS4.
Sony have surprised several people with their cross-generation approach when it comes to major first party releases. Sackboy: A Big Adventure and Marvel’s Spider-Man: Miles Morales both released for PS4, and Horizon Forbidden West will as well, while there are questions about God of War: Ragnarok as well. Sony have said on multiple occasions that they’re going to keep releasing games for the PS4 for at least a couple more years- but one game that definitely won’t be cross-gen is the upcoming racing sim Gran Turismo 7.
Sony recently published a new video highlighting some major games that are going to be releasing for the PS5 in the near future, and confirmed while showing off Gran Turismo 7 (starting at the 0:21 mark) that the game will be coming exclusively to PS5, with no PS4 release planned. The video states that the game will launch in 2021.
Meanwhile, Sony mentioned in a previous video that Gran Turismo 7 was one among several upcoming first party titles that was due out in the first half of 2021. It seems, however, that they have now updated that video to remove that launch window for the game- so it might not necessarily come out in the first half of the year.