Having seen this happening in the past, pre-AI, the answer is usually that they don't. They just stay on that version forever. Or it's maintained until the original author moves on, after which it's someone else's problem to figure out how to move back to the upstream, which has now had years of changes.
Having seen this happening in the past, pre-AI, the answer is usually that they don't. They just stay on that version forever. Or it's maintained until the original author moves on, after which it's someone else's problem to figure out how to move back to the upstream, which has now had years of changes.