From all accounts I've heard, the offensive plan is Whipple's passing scheme and Frost's running scheme, ie the overall running scheme is basically the same as before. And from what I've heard, most of improvement is on the running side. So if the overall running scheme hasn't changed but performance has improved there, wouldn't that mean that it's the OL coaching philosophy change that made the difference?
And let's not pretend that the problems with the offensive line were all schematic. The number of penalties they racked up were arguably an even bigger problem than the blocking. That falls squarely on Austin.