That's because that's the date they printed it. If you go to your county records office today and ask for your county's birth certificate today, they will put the date it was printed, along with your birth date.
I know this because I have had to get extra copies of my birth certificate before.
A new copy printed today is no less valid and no less official than the one given to your parents when you were born.
You are completely missing the point. The fact that it had 2007 on it means that it is supposedly a copy of what is there now NOT the original that is sealed because of the adoption.
The adoption very likely changed Obama’s name. So who went back in and changed his name again????? and when????
Obama supposedly can’t get at his original birth certificate because he was adopted. I am not sure this holds true if it is just a one parent adoption versus an anonymous adoption.