Mozilla isn't committing to manifest V2, they're just making changes to V3 that are different than what's specified for the sake of compatibility with what people want. They still intend on migration.
Finally, while this is a more personal opinion, the AI integrations that Mozilla has been working on (including some of the work on large language models) is isn't particularly contributive to the Mozilla manifesto and doesn't have much to do with the web itself. It's simply seeking something out because of hype