This trade is a can't lose move.
What if Kyrie is just the same player he's been for the first 6 years of his career? What if Kyrie gets seriously injured (something that's happened many times before)? What if Isaiah returns to the level he played at last year? What if the Cavs win the lottery? What if Kyrie leaves in 2 years? There are many, many ways for this to be a "lose" move.
Ok, but how likely are these things? Better yet, name a single guard in his 20's that we acquired from another team or via free agency who served as a distributor for us, and didn't get better. Not saying there isn't one, but Jordan Crawford, Evan Turner, and IT make me feel pretty [dang] confident that Kyrie's game is going to improve as early as this year.
Jordan Crawford? He was barely an NBA player before, during and after his Boston tenure. He had a couple of weeks of hot shooting. Brad gave him minutes and played him more at PG than he had been used at other stops because we basically had no other option at PG. That didn't really make hm a better player. Look closely at who he was at WAS before he came to BOS and who he was for GSW after he left. He was the same low-efficiency player. If anything, it wasn't until this LAST year, playing for NOP at age 28 after 2 years OUT of the NBA (playing overseas) that his game has _finally_ shown notable improvement as his scoring efficiency took a huge leap over what it was all his prior stint in the NBA. Maybe his coaches in China were better than Brad? Or maybe it is just too small of a sample (another hot shooting streak?)and we'll just have to see how he does this coming year?
And other than becoming a pretty good defender while he was with us, Evan Turner was and is a thoroughly average NBA player. Again, our roster at the time had a need for what he could do and he got minutes. But he didn't become a magically different player for us than he had been before. His shooting & scoring efficiencies pretty much were and are the same as they were before he came here. Thoroughly meh. Evan always had the ability to pass and Brad gave him that role so his assist rates jumped up. But again, that was largely because of lack of alternatives - Marcus Smart just wasn't ready yet to run the offense. And while his assist rates jumped, so did his turnover rates. The moment Evan got to Portland, his AST% (and his TOV%) dropped right back to exactly what it was before.
Similarly, while Isaiah's year last year was amazing, he came here already as an elite scoring point guard and hit the ground running the moment he arrived in Boston. He was already a super-efficient scorer and he didn't have to learn our system or be coached up - his scoring efficiency was elite before he got here and continued elite with his first minutes on the floor for us. The difference this last year was with the addition of Al Horford (and the much better outside shooting provided by guys like Avery, Jae & Kelly), Thomas for the first time in his career had a little bit of help on the floor. The rise in his already great efficiency to a next level was a natural extension of what he'd been doing before with no help. His overall scoring efficiency for his tenure in Boston (59.4%) is only a little bit higher than what he had posted his whole career prior (57.6%). His assist rate in BOS (32.8%) was almost identical to what it was his last year in SAC (32.2%). Again, there was no magic transformation. Brad gave him minutes because he was (by far) our best option for the PG role. And Isaiah executed.
That's what coaches do. They put players on the floor. And the best coaches (like Brad) put their best players on the floor as much as possible and do their best to manage it so other players are on the floor when the match ups are favorable. I.E., to put them in position to succeed. But it is up to the player to execute and to become who they become.
If Kyrie is going to become 'next level Kyrie', it is because HE is going to become that guy. Not because Brad is going to sprinkle magic pixie dust on him.