Some of the forgejo devs apparently believe that a collective copyright header is the same thing as a copyright assignment: https://github.com/go-gitea/gitea/pull/27455 & https://codeberg.org/forgejo/discussions/issues/67 I disagree on that point personally, but is there precedent here anywhere in the world?
Now that forgejo is not hard-tracking the gitea source, maybe we'll see in a year or two which project has better technical velocity or whatnot. IMO it's a coin toss between the two at this juncture.