Github user je-ik commented on the issue:
https://github.com/apache/flink/pull/5185
@StefanRRichter I think that was exactly the initial idea, but then we came
into troubles with the savepoints and changing list type. Also as @aljoscha
mentioned, it can be confusing for users to see `MapState` instead of
`ListState` after inspecting the savepoint. Unfortunately, I currently don't
have time to work on this, so if anyone would be interested in getting this
done, that would be awesome.---
