Whether Kyrie re-signs with us or not does impact the long term value of the trade but in any case, we have a better chance, perhaps much better chance, to re-sign him than if we didn't trade for him. So there is value there either way. Plus he did waive his trade kicker which is a pretty good indication of his intentions. Intentions can change but I think he intends to stay. And he has played and fit in better than most thought.
As for what we gave up, IT, Crowder, Zizic, BNK pick, all of them have less current value than the perceived value at the time of the trade. This is subjective admittedly but still pretty clear.
As for what CLE was able to flip them for, can you imagine that we would have traded IT, Crowder, and Zizic for Hill, Clarkson, and say Nance (it is impossible to completely match this up). This is somewhat comparable value if you know that IT is not going to be close to 100% all season but otherwise, no way.