Since I'm awake now after a refreshing 6 hours of sleep, I'll go ahead and postulate why 100 points per game might be a bridge too far.
http://www.basketball-reference.com/teams/POR/stats_per_game.html
So in Stotts' three years as coach they broke the 100 points mark twice; which seems on the surface to suggest that he must be pushing the pace or something, but when you start to pull the numbers apart to see what made the offense so prolific the past two years it really only comes down to two things. A high volume of 3 points shots, shot at a good percentage. Everything else: 2 pt attempts, 2 pt %, offensive rebounds, steals, free throw attempts, FT%, etc., are all well within a standard deviation of each other (mostly).
Now I know he'll try to adjust his system to account for new players with totally different strengths and weaknesses, but since he's already said that the team's defensive philosophy is unlikely to change, I'm not sure I would count on a huge uptick in points created off of turnovers or fast-break points. Compounding the problem is the fact that we have a real dearth of shooters/scorers on the team. Some have hypothesized that we'll hit teams with a steady diet of pick-and-roll with a more attack oriented roster - guys that like to get close to the hoop to score - but without the spacing provided by shooters who can catch and shoot from the corners consistently, it's easier said than done. Not to mention that this team is probably going to take awhile to gel and learn each other's sweet spots.
So putting aside what the defense will look like, wins and losses, and overall points-differential for the moment. When you look at this team who are the bonafide scorers outside of Lillard and maybe McCollum? That probably sounds like a rhetorical question, but I'm serious. Do guys like Aminu, Henderson, Plumlee and Davis have the chops and I've just never noticed? Full disclosure, I've watched them play very little.
I don't mind being wrong, but I haven't seen a compelling case yet for why this team will be any good at generating points on a consistent, night-to-night basis.