Ideally all references would be removed from the docs. If not a release note to explain that those options are no longer available and docuement could not be updated in time.
I'm removed this from table 4.1 (no relnote required): <row> <entry> <command>--store-async <yes|no></command> </entry> <entry> If <command>yes</command> (or <command>1</command>), the broker will use an asynchronous journal for message persistence; if <command>no</command> (or <command>0</command>), the broker will use synchronous storage. Defaults to <command>yes</command> (asynchronous). </entry> </row>