Update on that. Let me remark again that "sharp" means very slightly sharp, something that you can feel if you put attention to that seam detail and check with the finger, but not at all the first thing you notice about these machines.
Some data after checking 17 exposed models:
View attachment 2089796
The sample is small but gives a hint about how it goes. ~50-60% of the Air models edges are flush and smooth, the other have some "sharpness" that it seems is ok with build tolerances. That means only ~25% of the airs have both edges completely flush and smooth.
With the Pro models it's a non-issue as the vents are way sharper and you don't even stop to check the mini-sharp seam between plate and body. With the airs, as the body itself is smooth, with no vent openings, the seam feeling gets amplified. Not in the table, but with the older MBP/MBA designs which have bigger seam cross section radius all seams were 100% smooth.
Sharing it to show anyone else with the same inner debate that this is just how it is. You can get a flush one or not. Reminds me of the IPS panel lottery. Just accept what you get or keep replacing it until you get the perfect match.
Over all, my unit has a really nice IPS panel so not gonna risk to lose it just to get a smoother seam, specially after this sample showing I have a ~75% chance the replacement unit comes with the same """issue""". Maybe it gets outdated if Apple fine-tunes their CNCs... But there are many things to do until then with that awesome machine hahah
Cheers!