I'm sorry to be late to the party but let's face it point by point:
1. To blow air compressor directly to the screen to remove the dust I don't think it's a good practice, you're giving tons of power to particles that you don't know 100% if they'll be abrasive with enough speed, and possibly is what caused the first micro-scratch, maybe it wasn't dust or it was but mixed with other things, always best idea is try to remove dry particles by just "caressing" the screen with the microfiber cloth, let them fall and collect from hinge. If something doesn't comes off, use the microfiber damped with distilled water carefully as instructed by Apple (you can apply also Isopropyl alcohol or ethyl one on the % they recommend with wipes)
2. You did nothing wrong with your microfiber cloth, if it's a lint free one and has relative quality as Apple states, and you weren't too harsh when cleaning it (maybe even with all of that the right "particle" could create it) ... of course the cloth itself could do it, but if it was new and well packed, it shouldn't cause the issue unless it's a very bad one. I've used Amazon Basics one not applying too much pressure to clean and then to buff, and screens on MBP M1 and M1 Pro came pristine. I've used distilled water and Belkin Iso 70% wipes as well, inspected with flashlight, not a single issue.
3. Since you don't know what really created the situation and the scratch, blowing or cleaning, you can go to Apple and tell them your story, of course, it's better to have AppleCare+ for this kind of things, and if you can purchase it, I'll do it. Once it's done, replacing the screen will be 99$ if somehow you're honest, at the end, it's created for these kind of accidents, and IMHO, this accident is by almost following the guidelines, let me explain. Similar situation could be happening if accidentally a particle from your keyboard hits the screen when using compressed air as Apple tells you to do to clean the keys, or when removing particles from the screen, and you did follow the guidelines regarding the microfiber.
4. Maybe the particle that created that scratch was a tiny lose metal bit from its origin, who knows, if you can show/explain the story to a Genius within an Apple Store, even if you need the flashlight, they'll try to help, always being honest of course. I came with a different problem from the factory on the screen and they were nothing but helpful, and my AppleCare+ wasn't still purchased.
Sorry for the TL;DR, but I think you still can do something, and IMHO, it's not 100% your fault since you "almost" followed the guidelines.
edit: spelling