A year ago, OnePlus company announced that as part of the merger with the related company Oppo, the OxygenOS and ColorOS interfaces will be combined into one. This was to unify the system interfaces on phones from both manufacturers and it was announced that phones with a unified version of the ColorOS interface will appear in 2022. However, OnePlus unexpectedly announces that an event called Open Ears Forum will be organized on 28th of February, the subject of which will be the new version OxygenOS.
It is interesting because, as previously announced, OxygenOS brand was planned to disappear from the market in 2022. So far, OnePlus has not provided details about the conference. It is possible that the planned system unification in the OnePlus and Oppo phones has been postponed, hence the OxygenOS version 13 will appear on the market. It is also possible that despite the unification of the systems, the naming and general branding of the system in OnePlus' phones will remain unchanged, while from the programming side, the system codes in ColorOS and OxygenOS will be the same.