Well, yeah, but is that really necessary? They demonstrate intent, they support the accuracy of Google's view of the situation, and I'm pretty sure they'll make it harder for Oracle to paint Google's actions as tortious. It's similar to how you'd have a hard time suing somebody for injuring you if you admitted you jumped in front of their car to get money out of them — that's not a contract either, but it won't help your case. If even Oracle believes that what Google is doing is OK and doesn't constitute infringement, then that paints them as rent-seekers rather than an injured party.
-Google has to prove and convince the jury that they obtained a license or a legally binding agreement to use Java. So they need to present evidence that they have those. Any statement from an employee, even from the CEO, is useless if there are no legally binding contract or license.
-Oracle only has to prove and convince the jury that Google willfully and knowingly ignored required licensing agreements. So they can present emails and quotes from employees and executives and the emails alone can do a lot of damage.
Juries decide on facts, though, not laws. They can determine whether or not Google thought a license was required, but it's the judge (or more likely an appellate court) who will decide whether it actually was.
