WSUS Rollups to main server not accurate

Hello,

Simple installation with two servers: main and replica.

The replica is set to roll up to the main server.

Part of our normal process is to view all computers and sort by last status report.

When we do this on the replica and delete dead servers, they are not automatically deleted on the main server.  The status of replicaiton show that the date of last rollup is in line with the nightly synchronization.

Do we have to delete machines in both places?

Thanks,

Kim