iPhone 6s? Are the iPhone 6ses? Instead, Schiller took exception to the pluralization of general products like the iPhone or Mac. Ask any normal person and we're quite sure that most people would say plural would be iPhones or Macs. However, Schiller is not a normal person, it seems. According to Schiller, "One need never pluralize Apple product names." Schiller asserts that Apple product names occupy the strange space as the words deer, scissors, or pants, which are the same whether singular or plural.The pluralization discussion isn't even the more obvious one that you might expect, as in: How do you refer to more than one
This means, Schiller said, that it would be correct to say, "I have 3 Macintosh," (as though anyone in the word doesn't call an Apple computer a Mac). This means the sentence "The school has 25 iPad" would be completely acceptable. However, if you can't bring yourself to say it that way, the official Apple style guide suggests the correct way to do it is to add a descriptor, like "5 iPad tablets" or "69 iPhone devices".
Of course, the whole argument is ridiculous, because not only are these just the ways Apple would like you to say it (which has no bearing on how normal people actually talk), but CEO Tim Cook himself has broken the rules by saying the words "iPhones" and "iPad Pros" in the most recent earnings call.
So basically, just say what you want. The Apple Style Guide isn't the dictionary so the rules don't really matter to anyone outside of Apple itself.