I think there are two main factors that determine what Gaudette's role with the Nucks will be:
1. His performance next year will be more indicative of what his true ceiling is. This year he played on the best offensive line in the NCAA and that inflated his numbers; observers from the NCAA has Gaudette and Aston-Reese as the drivers on the line, with Sikura being the passenger.
2. How much weight Pettersson can put on. I personally believe Pettersson has one of the highest in his draft year, but the guy is built like a twig as of now. If he is going to develop physically like his brother, he might be closer to 175-180 lbs during his 20's instead of the optimal 190-200 lbs range. If the former case is true, management might prefer to play him on the wing.
If Pettersson doesn't develop physically enough, I could see Horvat and Gaudette (assuming he develops well in the NCAA) in a 1B/2A situation down the middle.
If Pettersson does develop well physically, I have a hard time seeing Gaudette challenge him for spot as the top centre. If this is the case I could see Gaudette challenging for Horvat's role as the 2nd line centre.
These are of course all lofty expectations, but I think there is a consistency to Gaudette's game that would make him a good 30-35 point centre if he doesn't hit his offensive ceiling.