Is this needed and how do I do this?
There are some caveats (bugs) resolved in 7.0(2) listed on the Release Notes. It's not a requirement, but you can upgrade your server.
BTW, not sure is you are using Unity Enterprise or Unity Connection.
Please refer to:
*** Release Notes for Cisco Unity Connection Release 7.0(2) ***
--> Upgrading from Cisco Unity Connection 7.0(1) to 7.0(2)
*** Release Notes for Cisco Unity Release 7.0(2) ***
--> Upgrading to Cisco Unity 7.0(2)
This is a straight upgrade.