The M728 was designed with combat across a broad spectrum in mind. From urban to desert to jungle, the M728 was built to destroy obstacles to the manueveur force.
Does the Assault Breacher Vehicle provide the same support? Quite honestly I don't think it does. Line charges are able to defeat some obstacles but probably not the majority of them. Its a powerful vehicle but the lack of the 165mm gun found on the M728 will be missed.
Time will tell but if the Army and/or Marine Corps ever finds themselves in urban combat against a skilled opponent, the lack of a bunker busting/obstacle clearing gun will NOT go unnoticed.