Bleh, reserving copies is literally a thing of the past, at this stage digital sales have slowly become more prevalent over physical copies and you can't run out of digital copies to begin with. If people pre order, it's not to reserve a copy anymore, it's more for the bonuses and the ability to pre load it before launch. Not saying there aren't cases of lacking copies, but in this day and age it's not so common and when it is, it's typically the special editions more so than standard.
I'm also not a believer that they get your money when you pre order, for one money doesn't transfer till a week from launch so that's plenty of time for people to cancel if they end up needing to or dislike what they've seen marketing wise. 2 since they don't get that money till launch, they're having to use their own money to build the game, it'd be pretty ignorant on their part slack off with their own money potentially going to waste. 3 even "if" pre orders ever was a guaranteed thing, we live in a world where things don't get produced without funding. So it wouldn't be like it's wasted money, you get what you pay for, you paid to fund developements of a project, not it's quality.
I don't care if 343 gets away from pre orders, I wouldn't see much of a point other than pleasing a crowd that sees it as an issue but then you'll have others asking where the special bonuses are for doing so.