For me the problem isn't really the preorder, it's just the fact that, unlike early timelines, when you give a release date for a product that has been in development for 2 years, 2 weeks before the release, you are kind of sending the message "we're finally done, we are at a stage where we're 99.99999% sure this is when it's going to release"
Honestly as the guy on Reddit said for me it wasn't unfeasible that the patch and the plane was already set in stone and ready for release when the video dropped, and they were just waiting just to build up hype, and to give CCs visibility.
I'm really disappointed and confused (as a beta tester myself - not for DCS), of how a huge game breaking bug only came up during "final check" as BIGNEWY said, and if it did, surely the builds before that were still playable enough that testers got along fine without discovering that bug.
It's impossible to take decisions from the outside, but it's hard to understand why this was better than a patch followed by a hotfix, if anything, just so that the community wouldn't explode