Current OpenShift must-gather collection document [1] states following which can be an issue as customers have many clusters and each must-gathers must be unique for them to identify even though provide --dest-dir as option which is also not default option for them :
$ tar cvaf must-gather.tar.gz must-gather.local.472290403699006248 

[1] https://docs.openshift.com/container-platform/4.18/support/gathering-cluster-data.html

Every time as must-gather is collected

1.   Doc link https://docs.openshift.com/container-platform/4.18/support/gathering-cluster-data.html  

2. must-gather script must tar with unique cluster ID with date of collection or change the documentation to manually provide the date and cluster ID. 

e.g tar cvaf must-gather-`date +"%m-%d-%Y-%H-%M-%S"`-$CLUSTERID.tar.gz must-gather.local.426787175854303238/

must-gather script must tar with unique cluster ID with date of collection

e.g $ tar cvaf must-gather-DATE-CLUSTERID.tar.gz must-gather.local.472290403699006248