Plot device information (via page setups) is saved in the drawing. The only way to prevent the message from coming up would be to change your Printer Configuration Search Path to your old version folder. But that would only avoid the message. You'd run into problems trying to plot to these old device set-ups.
The only way (I know of) to make the message go away is to open the drawing and change the plot device in any page setups saved in the drawing.