Pending Restart will do restart if upgrade to the new version

I have some clients (Servers) which required restart but i can not restart because of application running

i want to upgrade SEPM 12.1 to 14,  if i do upgrade SEPM 14 the clients which are pending restart will restart automatically or not? SEPM i can restart but i can not restart. after SEPM 14 upgrade client pending will stay in same state or restart ??