That's a giant pile of wrong.
The Nets picked up Kyrie Irving, Taurean Price, DeAndre Jordan, Garrett Temple, Wilson Chandler and some guy named Kevin Durant (though his availability next year won't be until late if at all). That's on top of Dinwiddie, LeVert and Allen, who have their best years in front of them.
The Pacers grabbed Malcolm Brogdon, T.J. Warren and Jeremy Lamb on top of getting Dipo back. That team is so much more dangerous that it was last year. If anyone's picking a "sleeper" in the east, I don't see how Indiana's not the choice.
The Celtics brought in Kemba and Enes Kanter (whom you were aching to keep) in addition to having a young core that's only getting better. It's year 3 for Jayson Tatum too. They've also got a new pile of kids who looked really good in Summer League, including Tacko Fall, who thinks Mo Bamba is a short-armed midget.
Al Horford and Josh Richardson are different than Jimmy Butler and J.J. Redick, better overall defense (J.J.'s a pylon) and rebounding, possibly better ball movement (Al's a great glue guy). Yet Philly has a much deeper bench. It's loaded for bear.
Milwaukee's down Brogdon, but Giannis is only 25. They've still got an array of shooting around a stud player still coming into his prime. They won 60 games last season and there's no particular reason they can't do it again.
Toronto's worse, which perhaps puts them into a push with the Magic (unless the Raptors decide to sell and rebuild, in which case the Magic ought to be at the front the line for Kyle Lowry).
Basically, all the teams you underrated last year you're underrating again.