Nope. What you are referring to is marked plain TMY. The mark 400TMY was introduced at the time of change in coating facility in 2002 or 2003. At that time, the development time and packaging changed, but the light sensitive emulsion did not.
Marking 400TMY-2 is given to the latest emulsion introduced in or around 2007.
Ok, I see. You are referring to what is printed on the film edge.