I don't think this date is just symbolic because of Executive Order 6102 and its abolishment. It seems like overthinking to me, so it might just be the day Satoshi was born. This person might have left this true date back in the times when Satoshi wasn't that popular, so there was no point at fully hiding one's identity up to the small details. So Satoshi, whoever you are, I want to thank you for your creation that's been truly revolutionary and literally changed the lives of dozens of millions of people who now use it. I hope you're alive and well, possibly even reading this stuff from time to time while staying aside and doing something else with your life.