I think that we should add an explanation on the rename request form page concerning anonymity/privacy when user wants to hide an username that contain his real name.
There are such information, but on enwiki, not on every wiki that use CentralAuth / Special:GlobalRenameRequest. See record element of the template CHU: https://en.wikipedia.org/wiki/Template:CHU
Clerk note: As your request appears to be related to a desire for anonymity/privacy, please note that a permanent log record will be created noting your previous name. As such, you might consider simply creating a new account and having your current account renamed to something random and abandoning it. Please advise.
I think that we can add such information in the existent message globalrenamerequest-newname-help : https://meta.wikimedia.org/wiki/Special:GlobalRenameRequest?uselang=qqx
I purpose this text :
If your request is related to a desire for anonymity/privacy, please note that a permanent log record will be created noting your previous name. As such, you might consider simply creating a separate and independent new account[Special:CreateAccount] and having your current account renamed to something random and abandoning it. More information[Link to Mediawiki.org help page].