I preorder from time to time but it has to be something with some sort of track record. For example I preordered Baldurs Gate 3 because I absolutely love Divinity 1 and 2 and D&D so was a very high chance that I would enjoy BG3. I also preordered Diablo4 because I loved Diablo 1,2 and 3. I will undoubtedly preorder Civ 7 because I loved Civ 1,2,3,4,5 and 6, getting over 1,000 hours played out of both 5 and 6. So thorough was my enjoyment of Pathfinder that I had no qualms about preordering Pathfinder 2 (ended up with over 300 hours played in both and 100% them both) and as a result I have already preordered their next title - Roguetrader.
If they ever make another Metro game I'm pretty much odds on that I would preorder it considering how much I liked Metro 1,2 and 3. Given how much I loved the Anno titles, I'm almost certain to preorder the next Anno game.
I dont really preorder "unproven" or unknown titles but if I've got history, sometimes going back decades in things such as the Civ games, then its not unusual for me to preorder.