If all your clients have Outlook already updated, then you won't need the Exchange Calendar Update. This update is for Exchnage only - not for Outlook clients.
All servers and workstations need the windows update for updating DST. If they do not get it in time - then you may be unable to logon to the domain. (but the TZMOVE tool only needs to be run on clients that have Outlook running (the ones you want the appointments to be correct after the time change)