Demon’s Souls Remake is a PS5 launch exclusive that will be out on November 12, 2020. It has been listed for PS4 by a Hungarian retailer.
In a new update, the Hungarian retailer Media Markt has listed Demon’s Souls for the PS4. This listing appears to show a box art for the PS4 version which is the same as the PS5.
Source: https://twistedvoxel.com/demons-souls-remake-listed-ps4/