@ninetynineAu "In other words, I suspect convicted sex offenders may be trying to trans-wash their history, knowing that gender reassignment offers certain "privacy" protections."
Yes that would provide a strong motivation and there are plenty of unisex names to choose from. Also this could stem from wanting a fresh start not 'just' a desire to reoffend with impunity. 'It's not fair I shouldn't be on the sex offenders register loads of people have done way worse things than I did' thinking iyswim.
Society has judged they should be on the sex offenders register, doesn't automatically equate to the sex offender agrees and considers this fair and reasonable. And for virtually everyone if you believe the rules are unfair and you are being treated unfairly it makes easy to justify lying or cheating to get around the 'unfair' rules.
All of which to say, if we create a loophole, they will use it.