Are Unis more likely to give you an offer if grades achieved already?

Basically what the title says, are unis more likely to give you an offer with achieved grades or predicted grades?

For example lets say student A did their A levels last year and decided to reapply with A*AA, would they be more likely to be given an offer from a competitive uni than student B who is predicted A*AA? Do unis prefer already achieved grades?

If so does this mean you have a better chance into getting into your top choice university after you take your A Levels if they previously didn't give you an offer? Does having your A Level grades achieved already make you more competitive?