I think we should probably wait at least a month or so before worrying about minutes. Given that this was the first game of the season, the first game in a week, and a game against their biggest competition for home court in the East, there is plenty of reason to believe the minutes were an aberation compared to the rest of the regular season, and closer to a playoff rotation.
My guess is we will see the starters minutes go down significantly tonight, and in most of the games in the regular season. But, for big games like last night, you need to expect a bit of a shortened rotation.