Hello, folks! I did a quick search and didn't find the exact info, so I thought I'd share...
I took a chance (albeit small), and as everyone would expect, the Airaid MIT for the 6.2 L works on the 2018s (Sierra in my case). Installation was easy and fitment is perfect.
I have no idea why Airaid doesn't just update their site to show the product works on 2016/7/8 with the 6.2L.
Order with confidence, I guess.