I never get the complete rage knockout gets into regarding "dead naming". It's such a stupid and immature way to view your past.
If I changed my name from Charles to Steve, well the public record, my license, my bills, my birth record, and all other documents would still reflect Charles unless I tried to get them updated. Changing your name (especially when not done legally) isn't some blanket pass to erase your history, and the idea that bringing up your past is harassment because you weren't wearing a dress at the time is beyond stupid.
Say they were to sign a legal name affidavit later for idk a mortgage or something. Are they really going to claim a lender is being transphobic when they ask them to sign a document stating they are also known by those names? Or that the notary kept giving them trauma by explaining the document to them and saying their old name. It's just ridiculous.