It Depends, is your EV Server installed on a DC then you need to put the VSA within the Domain Admins Security Group (because there is no locale Admin Group on a DC). Otherwise, if you have EV installed on a seperate Machine then you should take him out of this Group because you don�t need him within the Group.
But if the VSA is Member of Domain Admins then you have to change some Exchange Permissions in case of EMAIL Archiving, because the Domain Admin Group had per Default Deny Rights on Send as and Receive as.