[If they use a new sensor bar] they will be forced to sell new Wii remotes or they will use the old sensor bar. It's just simple logic really.
It's not simple logic. They would have to go way out of their way just to make it not work. It's just two sets of inferred LEDs. You can replace the sensor bar with candles and it'd work (depending on light in the room, of course). It's nothing special.
Or are you not talking about what I think you are? You worded it badly.