No, your tune IS the computer, so it stays even when you reset it. The only thing resetting it really does is reset the computer's adaptive learning thing (your car learns how you drive and acts differently based on your driving habits) which might even make your car drive better.
Sorry I'm kinda drunk right now so I don't know if that made complete sense but basically, no. You don't have to reset your tune. The only time you would ever need to reload your tune is to update it or remove it.