Don't understand how we can have an illegal shift on this play. The "Illegal Shift" Movement that draws B into the NZ occurs before the snap, and as a result of that movement B is in the NZ before the snap, which does occur while B is still in the NZ and A has not yet set. If we call illegal shift now we've got a live ball foul at the snap with B already in the NZ. We've got offsetting fouls at that point.
This is clearly a "coached" technique, that by definition is illegal and IMO a virtual "automatic" false start, blow & throw. Also, IMO the coach needs a talking to based on The Football Code preface in the rulebook.