When TWA Aviators and AAdvantage accounts were combined, AAdvantage accounts did reflect Aviators miles counting towards MM status with AA.
However, since others in this thread have reported that US has responded that BIS miles only will count toward MM status, I would not expect MM status from all account activity to count towards MM status with AAdvantage once both accounts are combined.
If it MM status happens with all combined miles, it's a nice jesture to those loyal to both airlines.
If MM status happens only for BIS miles amongst combined accounts, then it's a nice jesture to existing AAdvantage MM status customers that have had to play by BIS only counting since December 2011 [with the exception of those that jumped on the Citi Executive offer in December 2011].