The reason it shows your full name is because the Tech Community pulls your name directly from your Microsoft account, regardless of any changes you make to it on this site.
If you want to change your name in the Tech Community, you'll need to do so directly with these steps.
You would need to update your name here: https://account.microsoft.com/profile/edit-name
Then log back into the community using this link: https://techcommunity.microsoft.com/plugins/common/feature/oauth2sso/sso_login_redirect
That will cause your name to update in the community.
I apologize for missing your removal request in the other thread. For clarification, we don't allow users to remove their own account due to accounts being tied to their Office 365 account. I've removed your account.
