I would dispute this claim, e.g. Apple settles iPhone slowdown case for $500m[1], just the first link I found looking for "planned obsolescence apple" on DuckDuckGo. This is not exclusive to their iPhones as one can find with a quick search.
But they should have made it an option (it is one now on these devices) instead, they might have even come out good from it (as an android manufacturer wouldn’t even care about such an old device at the time).