Milan's transformation has been headlined by the shock capture of Italy defender Leonardo Bonucci, a key ingredient of Juve's recent success and widely regarded as one of the world's best in his position.
Having also lured the likes of Andre Silva, Lucas Biglia and Franck Kessie to San Siro, Vincenzo Montella's men appear primed to challenge for their first Scudetto since 2010-11.
And Buffon expects Bonucci's defection to spark a competitive title race as the Bianconeri chase a seventh consecutive league crown.
"Leo felt he needed a new challenge and Milan intrigued him," Buffon told Gazzetta dello Sport.
"Are Milan contenders? I think so… I look forward to a more balanced league.
"You'll see the value of teams who had a few seasons of decline.
Buffon has already revealed this season could be his last before he retires at the conclusion of the 2018 World Cup.
And the 39-year-old is eager to "appreciate the beauty" of his Serie A swansong.
"Yes, this year could be my final call and it's really electrifying," the 169-cap Italy veteran said.
"It will be special as a season but I want to make it even better by helping Juve repeat the beautiful achievements of recent years."