I really never thought the MillerA/B was a good way to characterize a storm.
I think his intent was to characterize zonal ULL with W-E moving systems as Miller B, and amped up full latitude troffs with S-N moving systems as Miller A.
However, whether the initial surface low forms in the TN/OH Valley or along the east coast is determined by the locations of fronts, CAD, moisture and small scale disturbances within the troff, or just ahead of it.
Sometimes both develop simultaneously like February 2010. Sometime there is one low directly over the SC/NC mountains like Feb 2006, kind of both a primary and a coastal..
Also storms can turn right or left as they track up the coast depending on amplification timing and confluence ahead of the storm.
So in summary I consider the Miller A/B a sometimes difficult to make distinction that doesn't tell us much about what the storms going to bring unless it happens to be one of the few that fits well into one category.. .