For those saying that they open up a max slot in free agency if Kyrie leaves, who are they signing into it? This class leaves a lot to be desired, unless you want to max out a 34 year old James Harden and pair him with Luka, or a 32 year old Khris Middleton. Even the restricted free agents suck:
https://www.spotrac.com/nba/free-agents/
That reasoning just seems like lipstick on a pig - cap space is nearly worthless to a contending team without the ability to sign good players with it. And to give up a future first and valuable rotation players for the privilege to it seems like a really bad idea.
Save for the slim, slim chance that Kyrie becomes an entirely different human than the one he's been for a decade, this trade seems like a disaster for Dallas, one last desperation heave to put a star next to Luka. They couldn't even get off bad salary like Tim Hardaway Jr. in this trade? Dwight Powell?
IDK, the team around Luka stinks, but I'd keep the powder dry until the summer when more players will be available and you can get a cleaner fit beside Luka (and someone who will reliably show up and play games for your team).