It depends on how short they are compared to the typical offer. And remember that it's often described as a "typical offer" and not "minimum requirement". If you want a course with AAB and you have ABB, they might still consider you as long as your personal statement is good and your teacher references are supportive. I've got predicted grades of A*AB and applied to unis with mainly AAA offers. So far, I;ve had an offer of AAA and AAB so it's a mix of factors in the end that get you an offer/rejection