OnePlus is doing something not a lot of phone manufacturers are doing, bring Android P to the two-year-old OnePlus 3 and 3T. Usually, phones get a two-year cycle for software update, so it was expected that Android Oreo would be the last updates for these phones. But the arrival of Android P on these devices come at a price. One is that these phones won’t get Android 8.1 update to better utilize development resources. Another is it’ll be placed at lowest priority, meaning OnePlus 6 and OnePlus 5 and 5T all get the update first. But for those who wanted to get the newest operating system, these tradeoffs might be worth it.
Source: Android Police