Honestly, its probably because as VP of the company, Cenx has info that the moderators (and even a lot of the team) might not have access to.
I can't blame the moderators for having a cautious, conservative approach to making public statements. If Cenx wants to make optimistic ones based on her current info, then that's her call, and I trust her judgement enough to figure she's probably right.
Feel free to be cautious as well, I wouldn't hold it against you. But give the moderators some slack, they are just trying to regulate expectations with the information they have!