I do not see why adding to Philip Morris's competitive advantage should have any bearing on what Congress does. That is, as long as the law would do what it is meant to, it should not matter if it helps one tobacco company over others.
Presumably, the regulations passed would be intended to reduce the amount of smoking that happens in the United States. This is really all that we should care about. It should not matter if one tobacco company has an advantage over the others -- all that should matter is that smoking be reduced and, thereby, the health problems that come with smoking.