As far as I know there is no plan to phase out Manifest V2 at Mozilla. As long as V2 and V3 are active in parallel it shouldn’t have a negative Impact on adblockers etc.
https://blog.mozilla.org/addons/2024/05/14/manifest-v3-updates/
We also wanted to take this opportunity to address a couple common questions we’ve been seeing in the community, specifically around the webRequest API and MV2:
- The webRequest API is not on a deprecation path in Firefox
- Mozilla has no current plans to deprecate MV2 as mentioned in our previous MV3 update
That said, I believe Firefox users have gotten a lot of benefits by having extensions made that work in both Firefox and Chromium-based browsers. I don’t believe there will still be as much effort for a Firefox-only extension but I believe there will be a sufficient number of motivated users and developers to still develop blockers and other extensions that take advantage of Firefox continuing to support MV2 and webRequest.
