MrBilliards
From my understanding, you would typically have to wait until your official transcripts are in before you'd be invited for an interview. Ask yourself, why would an admissions director look at an unofficial transcript that could have been altered if they can just wait for the official one? Why the extra work? Especially now when they have more applicants than they expected in Round 2, they'll only be reviewing those with fully complete applications.
However, there are exceptions, and in my opinion that happens if you are an all-star applicant. As in, you have a 760+ GMAT (99 percentile), stellar work experience at a global top firm, amazing recommendations from substantial leaders at that firm (better yet, Rotman MBA alumni), then they might invite you for an interview.
Your reasoning makes sense; however, I can tell you that, even though my GMAT is nowhere near 760, my application was reviewed before my official transcript was received. I even received an interview invite & interviewed with no official transcript on record yet. They did however say that any decision made will be conditional.