This is from last month, but I haven’t seen any discussion of it. Seems like Forgejo is now a hard fork of Gitea, instead of being a soft fork like it was over the previous year.
The main reason I’m posting it now is this: “As such, if you were considering upgrading to Forgejo, we encourage you to do that sooner rather than later, because as the projects naturally diverge further, doing so will become ever harder. It will not happen overnight, it may not even happen soon, but eventually, Forgejo will stop being a drop-in replacement.”
There are some advantages but generally it’s better for everyone to keep their copyright to prevent a company being able to take over and then deny users the software freedoms intended by the original license.
But everyone does keep their license. A company can not really take over in the sense that you lose your old code. They can stop developing in public but keep using your code, but so can you keep using the last public version and keep developing it. Or you can take your contribution and apply it elsewhere.
You’re right that the former license can’t be taken away from other instances.
Some projects chooses a license specifically to stop people taking code without sharing code back upon redistribution via copyleft (ShareAlike). Getting around that by changing the license defeats the purpose (projecting users software freedom).