OnePlus has already confirmed that it'll not have Project Treble on any of its current devices, including the recently launched OnePlus 5T. Now, the Chinese company has provided more information on the matter. During and AMA session on its official forums yesterday, a staff member explained that implementing Project Treble on current devices through an OTA update comes with risk of bricking the units. Here's what they exactly said: Project Treble requires a storage partition, by which the Android framework and vendor image are separated. However, because partitions were not required...
Source: https://www.gsmarena.com/oneplus_explains_why_it_opted_against_having_project_treble_on_current_devices-news-28616.php