Work around provided here https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs45790 is incomplete.
If you want ALL end points in a given policy updated to a given version, then just edit that policy and go to product updates section and choose the version of the agent. ALL end points using that policy will get updated.
IF you just want SOME of the agent to use a particular version, then duplicate the policy, choose the product version, move the endpoints the new policy; you can move them back after the update if that is your wish.