Plenty of people would buy it and the highest end part can always have the highest margin based on the fact that it doesn't have anything to compete against. The only reason to release anything else is that there aren't enough people who buy at that level.
Given the limited production capacity you'd want to come out with the high end first. The people who buy those cards will pay for even marginal upgrades and you won't have sufficient production to supersaturate that market segment at launch.
Historically, nVidia has always tried to release their big die first, because if production is going to be limited it's better to get as much profit as possible out of it to fund additional development. It's the reason why AMD launched the 7900s before anything else. There's more money to be made there.
I don't know if you were trying to make some historical reference there, but the 480 (GF100) launched before the 460 (GF104) by about two and a half months. The last time an X60 product launched first was the 260, but that actually based on the same GT200 die as the eventual 280, but with disabled cores.
In recent history, nVidia hasn't taken the approach you've outlined. They usually try to get their big die out first, and if they they run into the problems they just bin the parts or make sure that the eventual refresh solves any issues. Furthermore, pretty much any existing rumor points out that they attempted this same approach again, but for whatever reason decided to cancel their biggest die.
Your hypothesis does not make sense from either a financial or historical perspective, and furthermore existing rumors seem to go against it as well. I can't see any reason to continue assuming that line of reasoning outside of better support for your arguments.