So you work for Apple? Otherwise you are offering your opinion. You have no idea how many are affected. It could be 100s or 100000’s.NO. The affected iPads were, indeed, manufactured during that time period. ALONG WITH A BUNCH OF IPADS THAT WERE NOT AFFECTED. They can simply narrow the defect down to having occurred during that timeframe. That doesn't mean every iPad Air they made during that time is broken.
They likely got a batch of parts from some supplier, where one of the expected QA tests wasn't being done. Many of the untested parts would have passed that test, but some would have failed. If everything had been working properly, the parts that would have failed that test would have gotten rejected and not put into iPads in the first place. Instead, some iPads made it out the door with the defective part (along with a bunch with perfectly fine parts). They know the range of dates when the supply of improperly tested parts were used, so they know ones outside that range are not affected, but they don't know which of the ones in that range are affected. So, they say, "any iPad (manufactured in this date range and) experiencing this issue will be repaired free of charge".
They told you that a small percentage of devices were broken, and they narrowed it down by telling you that devices outside of a certain date range cannot be affected by this. That does NOT mean that all devices manufactured in that timeframe are broken, just that the devices that are broken were made during that timeframe. It really is just simple logic.
I’m going by what was posted and said by Apple.