In the create collection coordinator we perform an unconditional refresh of the cached database entry, to check if the database has been enabled for sharding. Since changing the "shardingEnabled" flag doesn't imply a database version change we can't rely on the versioning protocol to propagate this changes to the DSS.
Since the flag can only be changed to true but never set back to false afterwards, if the locally chached database entry already has the flag set to true, we can skip the forced refresh.