You can choose whatever method works best for you And I'm not suggesting otherwise. My Cleaning method differs from yours, but I also do use microfiber cloths as well. What Apple uses in the store and what Apple care suggests is two different things though. Whoosh is a safe Product for iPad displays, as that's how It's intended. However, AppleCare is only warning the consumer of the following from the link you provided:
Cleaning the iPad:
"Don't use window cleaners, household cleaners, compressed air, aerosol sprays, solvents, ammonia, abrasives, or cleaners containing hydrogen peroxide to clean iPad."
Basically it's advising the consumer to not use house hold products to clean your displays for those who might be ignorant. Furthermore, AppleCare doesn't suggest to NOT use products that are safe for iPad displays, because they can't speak for other third party manufacturers.
That said, you quoted:
"I would never trust anything except a microfiber cloth, dampened if necessary. Anything else is not likely to be any more effective without doing more to strip away the coatings already on the screen."
Which again is perfectly fine to use a microfiber cloth, but other tested products won't "Strip" away the coatings, especially if they are Tested and guaranteed like Whoosh and Clean Screen are, which are reputable. Regardless, The oleophobic naturally will wear off with general use, wiping with a cloth or intended cleaners. But I would not use a product that is questionable or if I was uncertain of it.
But I do agree to never spray any water/cleaner on the display of any electronic product, which also, the manufacturer on any display cleaning product should suggest this also. It's also overlooked, but important to read the directions.
Again, I don’t dispute that it is safe necessarily. All I am saying is if it is safe enough to not take off coating (more than just the oleophobic coating is on there), then it is no more effective than water, and therefore not worth paying for. If it is more effective, then I would not trust the claim that it won’t damage the screen after prolonged use.
By all means, use it if you would like. I am just trying to offer perspective for those that may hesitate paying for something that doesn’t do anything a damp cloth won’t do. To me, why would I pay for something that is not anymore effective and/or could possibly damage the screen?
By the way that link also refers to using water only in several sections.
EDIT: One other piece of advise for everyone. Try not to clean the screens very often. The more you rub them, no matter what you are using, the faster the oleophobic coating will wear.