If the requirements are A*AA, is there the chance of an AAA prediction getting an offer is other aspects are outstanding?
Of course there is a chance, but it does depend on both the applicant pool and the other elements of your personal statement. Extracurriculars and relevant experience will come in very handy in this case. My best advice (and advice I have seen others give) is to apply to this uni as an 'aspirational' choice, then a couple of on-grade ones, and one or two asking below your predicted grades (one of which you hopefully like enough to place as your insurance).
Unis do use grades as a guideline for if someone can do their course and I saw someone say somewhere else that if an applicant is two grades below they're unlikely to receive an offer. However if you have lots of extracurriculars and work experience they may give you a grade regardless if there is only one grade difference