Pita

Nice work, author. Let me contribute 2 quick obvious counterpoints ... perhaps 3, to the claim of the naysayers:
1. The naysayers' claim is baseless if they don't know for sure that net Profit as a % of ASP is higher for the more expensive phones. If you don't have that data, everything else in that claim is just baseless.
2. If the claim were true, Apple would schedule 'iPhone Cheap' release for a time when 'iPhone Expensive' supply historically usually catches up with the demand which happens about January of each year.  Would that be October? Less than a month from main release?!! Many 1st week orders of iPhone Expensive are still shipping in October. So, if we follow your logic, Apple will not succeed because iPhone expensive unshipped ordered will just get cancelled and people will simple buy iPhone Cheap which would then be available. We know that not to be the case.
3. The naysayers' argument would only be true if the most sold iPhone in the period between October and next August (when iPhone Cheap and iPhone Expensive are both in the market) ... ever happens to be iPhone Cheap. Extrapolate data from iPhone 5s and 5c.
4. In what universe does someone wake up in the middle of the night to rush to pay $1500 for something if he could pay $750 with certainty 3 weeks later?
5. If that were true, you'd expect the 64GB (cheapest) variant of the iPhone Expensive to be the first to sell out. But it was not.
6. If the argument is true, it will also be true for iPad Pro 2017 and iPad 2018 (Would the iPad Pro buyer have bought iPad if it was released same time? See how absurd that is?). 

Stating the obvious: Apple 1st wave buyers are not driven much by price. Again: Apple first wave buyers ... not driven much by price. Trying to understand Apple 1st wave consumer behaviour (where price plays a low determinative role ) with an Android consumer mindset (where price is probably the main determinant) leads to this kind of absurd abstraction.