Producer Naoki Yoshida seems to suggest a PC release isn't happening at all.
Photograph of a man in the middle of talking. The man is wearing a white shirt. There are some white flowers on the left side of the image.

When Square Enix first revealed Final Fantasy XVI it wasn't really clear if the game would be released later on PC. Most of us kind of assumed it would be since, you know, every other Final Fantasy has come to PC eventually. The initial trailer reveal, still up on YouTube courtesy of IGN, even says "also available on PC" in fine print at the bottom in the final seconds of the trailer.

There was even a rumor from someone going "dude, trust me" right when the game was first announced that said that Final Fantasy XVI would be a six month console exclusive before being released on PC. Come a full year after the initial PlayStation 5 launch, it was supposedly going to be free to be released on other consoles such as Xbox Series X|S.

Square Enix was quick to put up an edited version of that initial trailer on their own YouTube page. The edited version removes any and all mentions of a PC version.

Over the weekend, producer Naoki "Yoshi-P" Yoshida was interviewed at a Mahjong tournament. During the interview, Yoshi-P was asked whether or not a PC version of Final Fantasy XVI was actually coming. According to a "rough translation" of his response from Genki_JPN, Yoshi-P says that the initial announcement of the game coming to PC later is wrong. In fact, Yoshi-P seems to indicate that there isn't a PC release coming ever.

"Nobody said a word about a PC version releasing. Why is it like a PC version is releasing 6 months later? Don't worry about that, buy a PS5! (laughs) Sorry, I went overboard. We did our best so please look forward to it"
After that initial reveal trailer, any mention of any sort of a PC version hasn't been found anywhere in the marketing materials.

It could be that a PC version is still coming but due to the deal with Sony they aren't allowed to talk about it yet. It could also very well be the case that Final Fantasy XVI truly is a forever exclusive to the PlayStation 5. It would certainly be unprecedented but these are strange times we live in. Final Fantasy VII Remake was exclusive to PlayStation platforms for over a year before eventually coming to PC. Even then, it was then exclusive to the Epic Games Store on PC for another six months before hitting Steam.

The good news is that the PlayStation 5 shortage is nearing its end. The bad news is that you'll still need at least $399 (USD) or more for the hardware plus another $70 for the game itself. If plunking down almost $500 just for one game doesn't sound that appealing, maybe consider just waiting about a year or so to see if that PC version actually happens.