https://blog.mozilla.org/addons/2022/11/17/manifest-v3-signing-available-november-21-on-firefox-nightly/ https://blog.mozilla.org/addons/2022/11/17/manifest-v3-

https://blog.mozilla.org/addons/2022/11/17/manifest-v3-signing-available-november-21-on-firefox-nightly/ https://blog.mozilla.org/addons/2022/11/17/manifest-v3-signi... > Towards the end of 2023 [...] we’ll decide on an appropriate timeframe to deprecate MV2. https://blog.mozilla.org/addons/2024/03/13/manifest-v3-manifest-v2-march-2024-update/ https://blog.mozilla.org/addons/2024/03/13/manifest-v3-manif... > Firefox, however, has no plans to deprecate MV2 and will continue to support MV2 extensions for the foreseeable future. Seems they changed their mind in 2024.