Upgrading clients from 12.1.X to 14.X - reboot required?

So I've been reading the various upgrade documents from 12.1.X to 14.X (https://support.symantec.com/en_US/article.TECH236...) and I'm trying to track down if a reboot is required for the client servers running W2K8 R2 / W2K12 / RHEL 5-7 if I push out the upgarde via AutoUpgrade . I know for best practices it’s stated that the clients should be rebooted before installation - I have about 500 clients each with different owners so I'm trying to avoid scheduling 500 different reboot windows. 

Thanks