There is an unused rq_deleted field on the renameuser_queue table but the feature has not been implemented yet.
|Open||None||T103290 Provide limited access to Special:GlobalRenameQueue/request/|
|Open||None||T113938 GlobalRenameRequest: Allow to suppress rename requests|
We're running from time to time into cases that requires this feature. Could some resources be allocated to enable it? It's kinda user-unfriendly to ask an op to mess manually in the DB to remove the row. Thanks!