I'm in the same exact shoes. PC gamer with a relatively high end pc, but console game for the exclusives. I am definitely keeping my preorder. Not because it makes any sense, but rather because I'm a foolish early adopter who just has to have my new toys right away. I do want to play Killzone, so that helps. I'm also interested in Madden 25 as well. But beyond that, there isn't much worth talking about at launch.
If you have other use for the funds, probably cancel. If you don't have any immediate needs for the funds, then why not just keep the preorder? Afterall, with the holidays coming up, just never know when the system will become available again before they can restock depleted supplies.