Your analysis/insight apparently didn't take a look at the list of teams Woj reported Irving listed at desired destinations, all of who had strong coaches (except New York). Certainly the act of someone who -doesn't- want to be coached and wants to be a freelancer, eh? Popovich and the Spurs! The Heat and Spolestra! The Timberwolves and Tom Thibodeau! Boston and Stevens as mentioned by David Griffin? Psh! Who would want to be coached by -that- as a freelancer?
https://www.celticsblog.com/2017/8/7/16109514/david-griffin-includes-boston-celtics-on-kyrie-irvings-list-of-desired-teams
If the concern trolling is that Irving wouldn't take to it, maybe he shouldn't have, you know, sought out teams with strong coaching situations, as reported by those same 'insiders' you seem to place more of an emphasis on. That or you should have paid better attention to what they were saying and then ask 'why -would- Irving want those kind of situations if he wants to keep freelancing?'
It took Bradley a number of years to develop and keep improving his game, and -he- was a starter under Stevens for most of the same period, as a... let's see, has he been a six years starter? So his sixth year he kept growing and improving. Don't think Bradley has topped out yet. I have a difficult time believing that a player in his sixth year can't keep improving, especially at the tender age of 25. Hell, so did Gordon Hayward over the same time period, and I don't think Hayward has topped out yet either.
I think that the biggest thing with Irving in Cleveland was the lack of coaching stability and that, you know, the -scheme- in Cleveland was essentially "Give the ball to Lebron and do what he wants you to do". Giving him an actual coach and work a scheme designed -for- him and see what he does -is- a cause for optimism. Which is what an actual x-and-o analyst is saying.
God knows, I don't think Irving is a top-five player -now-. But he has the ability to do things and Brad Stevens -is- very good at coaching and will be looking more at what Irving -can- do and maximize that. Irving could very well be the same player -and- look much better because they'd actually focus on what he can do and not ask him to keep chucking up shots when the clock dies. Although I suppose he -would- be a better option for that kind of thing than Marcus Smart, so there's that, too.