There aren't just two options here. What you want is a response that is positive, but a vaguer way that doesn't actually make any predctions. What you want to hear is something that reminds you of how much you've already accomplished, reminds you that even if things don't work out it just means a delay rather than a defeat, and which makes the admissions process (win or lose) seem like less of a big deal in the grand scheme of things. Failing that, I'd settle for 'good luck'.
'You'll definitely get in', though, is a little too prophetic, and flies a little too much in the face of reality. It forces that rational, scientific of part of your mind to argue, because it doesn't like hearing things that are flat out wrong. However the emotional part of your mind was trying to avoid thinking about those exact arguments. That's why people get angry when they hear positive predictions stated as facts. It dredges up anxieties we put a lot of effort into suppressing.
BTW this never ends. I'm applying for residency now. My family is sure they'll take me.