What is the timeline for these changes?
Given Manifest v3 is still in the draft and design phase, it is too early to provide a specific timeline. We are currently investigating what level of effort is required to make the changes Google is proposing, and identifying where we may depart from their plans.
Later this year we will begin experimenting with the changes we feel have a high chance of being part of the final version of Manifest v3, and that we think make sense for our users. Early adopters will have a chance to test our changes in the Firefox Nightly and Beta channels.
Once Google has finalized their v3 changes and Firefox has implemented the parts that make sense for our developers and users, we will provide ample time and documentation for extension developers to adapt. We do not intend to deprecate the v2 API before we are certain that developers have a viable path forward to migrate to v3.
Keep your eyes on the add-ons blog for updates regarding Manifest v3 and some of the other work our team is up to. We welcome your feedback on our
community forum.