From what I've read about it, people are concealing the screen with cheap 3rd party protectors and or covers which *can potentially* lead to a garbled scan (with said cover installed) which in turn allows it to be unlocked by a non scanned print with that same cheap cover on top. So I see this as much as a defeat by the user as an oversight by Samsung.
Don't use a cheap cover and screen protector. Which I know Mike, you would NEVER do.
At any rate Samsung has acknowledged the "issue" and is working on a fix. Hopefully also to include a stern warning about avoiding cheap 3rd party accessories.
I don't even use a screen protector at all, so I'm not worried about it.