Jaylen is already a more valuable player than Kyrie.
Having a point guard like Kyrie (or IT) is great to run an offense, but any player on the floor can be that guy. When we had Evan Turner on the floor, we ran the offense through him. A number of wings run their teams offense. Horford, as a PF or Center, does a significant amount of this for us already.
Other than Turner, we haven't had wings to run our offense since Pierce. Crowder wasn't that guy. Brown and Tatum were too inexperienced for much of last year.
That appears to be over for the foreseeable future. Tatum and Brown showed in the playoffs that they are now ready to carry the offense for long stretches. Hayward is a proven ball handler and facilitator.
Don't we want Tatum scoring 25 ppg in 2 years? Shouldn't Jaylen be scoring 20 ppg? Shouldn't Hayward be scoring 20 ppg? Don't we want to give Horford touches too? We don't need a classic, ball dominant point guard any more. A big athletic guard that can knock down 3's and closes all holes on defense is better long term.
For the past several years, all the things that Kyrie is so good at have been desperately needed by this team. By the end of next year, those same traits will just be in the way. We now have 4 other starters who are huge, athletic, can create offense for themselves and others, and can play lockdown defense. Those 4 guys need touches and need shots.
Last year's playoffs were a sneak preview of what can happen. I expect Ainge would move Kyrie before considering moving Jaylen.