Assuming, of course, that the images of the newspaper announcements weren't created later.
bump for later
Okay, but that would seem a very risky hoax. My parents saved the newspaper that had my birth announcement. That was in the 1960s also.
There were a lot of birth announcements on that Obama birth announcement section of the paper that might lead one to suspect that some newspapers were saved and could debunk the Obama announcement. And even the theory that Obama was born in Kenya doesn't mean there wouldn't be a birth announcement in the Hawaiian newspapers. Upon arriving back in Hawaii, the person could register the birth as happening yesterday even though it happened a month or two prior. I don't think the DoH does an inspection of the baby to prove the date of birth is correct.