AP, that would be my assumption as well.
Since the films dissolve more efficiently, they get into the body via the sublingual action almost entirely - no large-ish amount of buprenorpine getting taken orally via excessive saliva. For the same reasons, less naloxone (if any) is being swallowed, thus it isn't activated as much either.
So far, the films seem to be a good option all around; they work better, are easier to 'break down' into smaller amounts than tablets are (ever taking 0.5mg from an 8mg Suboxone
tablet? *lol*) & generally are less expensive because there are still coupon programs & such. So, unless your health insurance covers the cost of the tablets but not the strips, it seems like strips are the way to go - at least for the time being.