> Although I guess it means you don't have to reconfigure immediately to try 0.15.
Yes, that's the key point. We generally try to make it so that upgrading between major releases should require no code changes, provided your code compiles and runs without warnings in the prior release. So the first step to removing anything is generating warnings. For API changes, this means they're deprecated for at least one release cycle before they're removed. Other changes are harder to know how to handle, but in this case a warning seems most consistent with this compatibility policy, no?