I"m not sure that it is, given that the empty interface is more annoying (IMO) than just wrapping a native map in a sync.RWMutex.

Especially considering that sync.Map just uses a mutex under the hood: https://github.com/golang/go/blob/master/src/sync/map.go#L19

edit: although reading the comments, apparently there are conditions where the mutex does not always need to be held. This would be an improvement over sync.RWMutex wrapping.