An elderly Beatty would be kept in a policy role

What role might David Beatty have received if he were still alive when the Second World War began?

Beatty would probably receive a safe policy or advisory post in Britain, well away from operational command, because of his age.

Age matters more here than Beatty's First World War command record. By 1939 he would have been far too old for the demands of active fleet command. The suggested outcome is a safe policy or advisory role in Britain, well away from active operations. Such an appointment would keep him out of an operational command that required a younger officer.