What is the Manage Replication Topology right needed for?
The QCS Tombstoning Mechanism is associated in Collaboration Services to the Retention Time for removed objects setting. When an original object is removed from a collection you subscribe to, the deletion is automatically synchronized to the subscribing forests, and the corresponding objects are hidden from the Global Address List. However, the stub objects themselves are not deleted immediately. Using the Retention Time for removed objects option, the deletion of the stubs can be delayed for a specified number of days. Thus, if the object is added to another collection during this period, the stub objects will be re-used. Using this option helps improve overall collaboration performance and decrease the load on the
Using the Manage Replication Topology right it reads the msExchHideFromGAL attribute of the stub object so Collaboration Services knows how long the stub object has been hidden from the GAL and can then tell as to whether or not this stub object needs to be deleted or held on to according to the retention time for removed objects setting.