[fregante]

Only pre-existing MV2 extensions can be updated. New extensions have had to be MV3 for exactly 12 months already: since January 17th 2022.

[karmelapple]

Thanks for the note! I had no idea. And that makes it all the weirder that Google postponed things, especially because it seems the community is relying on Google to provide guidance on how to do a lot of things with MV3.