Did you read my comment?Apple did; did you read? They introduced throttling to the iPhone 7 when the iPhone X and 8 came out, and they said they plan to enable this for future devices.
This article states that the people filing the lawsuit are claiming that Apple are slowing down their devices once newer models come out. Suggesting that it has nothing to do with the battery and purely with the fact that a new device has been released. Which is not true.