What is usually done to approve a post cutover UAT?

We're migrating a small remote pilot site to register to a central cm 6.3 in a Fxpod. The remote pilot site has a small number of trunks, extensions with VM on AAM and some SIP routing via SM. What would be considered for us (the customer) to sign off on the UAT?

The reason I'm asking is because I'm not sure if this is similar to a post cutover checklist vs a UAT.