Who knows what's really going on but from the outside it sure seems they should've traded him this offseason if they weren't planning to extend him. We don't know how bad the offers were but I don't see how his value is going to exponentially increase this season esp considering the roster here.
Last I checked the CAA website they had Collin up on their main page along with some of their other young stars (Randle, Mitchell, etc) so they obviously think very highly of him. Even if the Cavs FO secretly believes Collin is a 6th man I would be shocked if they dare bench him in a contract year. Sexton is also the lowest paid guy on the team at this point unless you want to count scrubs like Windler, Wade, or Stevens.
Sexton is going to be a restricted free agent. This is a fact.
Now... for
him, the situation is clear-cut. He's gonna want touches, shots, and lots of playing time. You can do a lot of stuff within those parameters – good and bad – but that's the starting point. No player going into RFA benefits from losing his starting spot or a featured role. You can talk all you want about proving you can play team ball, being unselfish etc. and doing it all off the bench, but this is the NBA and appearances matter a great deal. If you lose your starting spot and have a bunch of your shots taken away, that's gonna cost you millions of dollars in the offseason.
For the Cavs, it's much trickier. There's a number of ways the team can benefit from Sexton's contract year, and they're not always compatible with one another. It all depends whether or not the FO actually wants to keep Collin here long-term (albeit on a much cheaper deal than what he was looking for). I'm not at all sure about that.
RFAs-to-be are not great trade targets. I'm pretty sure teams aren't knocking the door down to offer the Cavs valuable assets when they can just wait and get the guy after the season. Sure, if the player is a true building block, a difference maker, you might take more of a risk during the season and sacrifice something in a deal. Sexton, though, isn't that. He's a luxury at this point.
If we suppose he won't be traded – I believe he won't be – and the Cavs do consider him a long term piece, they stand to benefit if his perceived league value
drops. There won't be many teams with money anyway next offseason, and Sexton may find his suitors dwindling fast if he has a meh season. On the other hand, if we're trying to win, having Collin play really well, in a big role, is something you want.
Lots of moving parts.