After all of the hype about the Chicago Bulls roster overhaul, the new era finally began Wednesday night with the season opener against the Detroit Pistons at Little Caesars Arena. But was this really the beginning of a new era for the Bulls or just a continuation of the evolution that began with last spring’s acquisition of Orlando Magic star Nikola Vučević by executive vice president of basketball operations Artūras Karnišovas? Before the Bulls’ 94-88 win over the Pistons, coach Billy Donovan didn’t care to put any labels on this 2021-22 journey. “I don’t know, this is my second year here,” …