Great question. One thing to remember is that the value of a piece of software that’s heading towards being un-maintained is much lower than one that has a clear maintenance path. One should be wary of single-maintainer projects. That said, the number of maintainers and the amount of code per maintainer would seem to be the important variables. In this case the code has moved from a repo with one (albeit absent) maintainer to another with one maintainer. Let’s call that neutral. However our new maintainer now has much more code to maintain so the risk has measurably gone up. It might be worth also taking into account how much code in total someone is responsible for across the cargo ecosystem.