Huawei has just announced that they will be starting a bi-monthly update for their 2017 and 2018 phones and OnePlus has stated they will be doing the same for their recent phones.
OnePlus has said that they will promise users two years worth of major updates, starting with the OnePlus 3 all the way to the OnePlus 6 with the T variants included. Other than that, they also promised that users will get three years worth of security patches on a bi-monthly basis. Lastly, they also confirmed that the OnePlus 3 and 3T will be receiving the Android P update later this year, however, that will be the last updates the phones receive when it comes to major updates, but security patches will still continue to come in.
OnePlus has been well known for supporting their older devices, the OnePlus 3 and 3T has got features from the OnePlus 5 and 5T which was unexpected. Unlike other companies that offer empty promises, OnePlus has given us confidence that even if you own their older devices, you will still get regular updates.