The Google Chrome team announced the deprecation plan for manifest V2. The transition was initially paused due to migration issues from manifest V2 to V3. In November 2023, the Chrome team released a new timeline [1]. All extensions should migrate to manifest V3 by June 2024. Coditude[2] is providing a free service to assist with the migration from manifest V2 to V3. Major browsers like Firefox and Edge are also transitioning to manifest V3. As of now, Safari has not announced any plans regarding manifest V3 but most likely they will follow.

[1] https://developer.chrome.com/blog/resuming-the-transition-to... [2] https://www.coditude.com