Hive determines if MachineSets are controlled by a MachinePool by checking the prefix of the MachineSet name in isControlledByMachinePool. If the MachineSet name is prefixed by "<ClusterDeployment Name>-<Name of MachinePool being reconciled>.*" then Hive will assume management of the MachineSet. This can be problematic in situations where users copy the existing MachineSets, append some string to the name of the MachineSet and then Hive unexpectedly deletes their MachineSet because their MachineSet matched the prefix and was not one of the MachineSets generated for that MachinePool.

https://redhat-internal.slack.com/archives/CE3ETN3J8/p1679420121788349?thread_ts=1679414827.276889&cid=CE3ETN3J8