Correct me if I am wrong but you pick two abilities, and since it does not state they have to be different you can pick the same one twice giving you a +4 to one ability?
"These humans pick two ability scores and gain a +2 racial bonus in each of those scores."
They give you a racial bonus to the scores, so if you pick the same score, like Strength, you'd get a +2 racial bonus to Strength then get a +2 racial bonus to Strength.
Same named bonuses don't stack, so no.
Racial bonuses specifically do stack, though.
I feel like colloquially "pick 2" involves making two different choices. Like if you can pick two toppings for your pizza, people are going to select like sausage and mushrooms not sausage and sausage.
