It seems Android O is now confirmed as the last major Android version update that will arrive on the OnePlus 3 and the OnePlus 3T. This comes from the company's Head of Product and via a recent blog posting on the OnePlus forums. The posting looks to answer a number of questions that OnePlus has reportedly received regarding the support for its now-legacy devices, the OnePlus 3 and 3T.
As such, the posting does specifically confirm that while Android O will be "the last Android version update" for the OnePlus 3 and 3T, both devices will continue to receive security patch updates "for the foreseeable future." As a result, OnePlus has also confirmed that following the update of the OnePlus 3 and 3T to Android O, the Open Beta Program will move to focus solely on the OnePlus 5. This may come as a concern to some owners due to the relatively young age of the two OnePlus 3 smartphones, although in reality this seems to be now in line with how OnePlus approaches updates to devices it no longer sells. For instance, last year OnePlus confirmed that the OnePlus 2 would see an update to Android 7.0 (Nougat) although that sentiment was reversed when OnePlus confirmed back in June that the OnePlus 2 would not receive the Nougat update after all. Leaving that device resting on Android 6.0 (Marshmallow), following its launch on Android 5.0 (Lollipop). So in some respects, the support now afforded to the OnePlus 3 and 3T will see them receiving one more major update, compared to the OnePlus 2.
The posting also looks to address what some OnePlus 3 and 3T owners might see as a software favoritism for the OnePlus 5. As OnePlus explains that during the OnePlus 5's launch period, the company decided to 'dedicate its efforts' during the first two months to ensure that the user experience on the OnePlus 5 was as good as it could be. A decision which seemed to result in some features released as part of the Open Beta Program being pushed to the OnePlus 5 and not the 3 or the 3T. On that point, the posting does look to reassure OnePlus 3 and 3T owners that features (as well as general software updates through the Open Beta Program) currently on the OnePlus 5 will also make their way to the 3 and 3T, providing they are features which marry with the older-generation device's hardware. Reading Mode on the OnePlus 5 provided as a direct example, due to this mode reportedly making use of the RGB sensor included in the OnePlus 5.