This will be a lengthy reply. First thing, please read this whole article.
https://wordpress.org/about/privacy/
About half-way down is a section titled “Retention of personal information” and there is a link there that outlines how any forum user can make a “Data Erasure Request”.
I am not linking to that form intentionally. I really do want you and anyone else coming across this to read the privacy statement in whole.
If you, or anyone, do make a data erasure request, when it is performed and implemented (and that can be a long time from now, there is a queue) the following will happen. This may not be a complete list and I am doing this from memory.
Any information in that user’s profiles here will be wiped clean. This includes your profile URL and display name.
The email, which is never published and cannot be viewed by visitors and regular users, will remain and cannot be re-used here on this site.
The userid in the forums will remain on the system. For example my userid is sterndata.
The user’s account will be blocked on this site and cannot be used any longer.
None of the user’s posts, replies or reviews will be removed from this site. Everything will remain public as it is now.
Data erasure requests are about personally identifiable information (PII). The forum here posts are not that and this topic is even less so than PII.
If you posted an email address or your physical address then yes, that would be redacted. That would be appropriate. I’ve not seen that here and you are not making that ask. You want the whole post removed and that is not done for the reasons I already explained.
If you do that data erasure request it will not result in your topic being removed. That’s not PII and not what the GDPR is about either.
For more background feel free to read the replies to this old topic about deleting topics.
https://wordpress.org/support/topic/gdpr-and-the-forum-of-wordpress-org/
It also addresses the userid in that topic as well.
If you have any additional question about tdata retention then please feel free to email dpo[at]wordpress.org. But again, there is a queue and please be patient. You will eventually get a reply but that may take weeks. I’m told it’s a long queue.