“OnePlus has announced a new system that limits who can unlock the bootloader on their phones. Stating reasons such as “data security” and an enhanced “system stability” […]. OnePlus has introduced a new procedure where anyone wanting to unlock the bootloader on their devices must first fill out an online request form for “Deep Testing””.
Even if it is for one region, it is still enshitification preventing phones to have custom ROM 🤦♂️
The Phone 1 and 2 have official lineage os support as well. Nothing is still bootloader unlock friendly (for now). Phone 3 is too new for LineageOS but is still an excellent phone with a good development community on their forums.