Yep, you're going to have to wait until Thanksgiving. Their website will take order with the discount that day, I assume until their allotment for this sale is reached. In store they should have some as well, if you're willing to stand in line.
I, too, have a N7 2013 which is/was great but it is getting a little small. And like you, I want something bigger, fairly future proof for a while, if there is such a thing with electronics. The Nexus 9 seemed like it fit the bill, all while bringing the price close to Apple territory.
For me it was mostly the screen on the Nexus 9, as I often read at night in night mode (inverted screen) and the light bleed was too strong and and uneven. I checked against my N7 2013 and my wife's iPad Air and they were a lot better. Whenever I use my wife's Air, I sure do miss the back button from Android!
The Air 2 and the Nexus 9 IMHO are comparable and dependent what you're using your tablet for, the iPad might even be the better fit as there are clearly more tablet-optimized apps for it, and I'm not sure with this price hike whether Google attracts more/better developers for tablets. If you're not "married" to Android or have a big investment in apps, nothing wrong with trying it.
I'll get my grand daughter a Samsung Tab Pro for $199 at BestBuy on Black Friday. With the Helium app I can transfer apps and app data to the unrooted Samsung, have done it for somebody and it transferred games with in-app purchases intact, both tablets were unrooted, BTW. I was impressed with the software. So should you go the Samsung route, something to keep in mind if you have the need for it.