My seat mate and I were going to use the meal vouchers for beer but they told us we couldn't reboard until the plane was ready to depart, as they were letting people reboard. And the E sky club closed at 10 so we can't just go wait there

Why does this aircraft have a center fuel tank if they can't use it? And if the issue was just a balance issue, couldn't they have fixed it more quickly by adding fuel to the other tanks?