In a recent interview with Famitsu, Silent Hill: The Short Message Producer and Director Motoi Okamoto talked about the decision to release the game for free.
Silent Hill: The Short Message is the first mainline title in the series since Silent Hill: Downpour, developed by Vatra Games and released in 2012.
Silent Hill: The Short Message is immediately available for free for the PlayStation 5.
Additionally, Okamoto mentioned that had Silent Hill: The Short Message been a paid title, the developers might have needed to add more conventional elements to the title such as combat mechanics, or include various different endings.