I'll stick my two cents in and say that Kent and Duncan are right to go - and I don't really blame them for the things they might say. We have no idea if someone at the club has lied to Kent - I wouldn't be surprised if Klopp told Kent that he would get opportunities to impress, and either things changed or Klopp simply said what he felt he needed to in order to keep a player he felt would be good for the depth. I can see how Kent would not take something like that well, and I'm not saying that happened, because we may never know. I just think that it's far from unlikely.
The reality is for these players that they want, and they need game time. Remember how Brewster was going to be in contention for the first team? Now he's vanished off the radar to a degree. It's hard for the attacking youngsters to get any time at a side where we have Firminho, Sala, Mane, Origi, Shaqiri to fill those positions. So I'm not going to slag off players who seek game time elsewhere, regardless of how they go about it. Liverpool are not some poor underdog against these players - I suspect that they would happily tell Duncan for the next three or four years how he would get a shot in the first team if it meant they could make their millions at the end of that time after giving him bare scraps of games. That's essentially what has happened to Brewster so far - he was going to leave, but then the club promised him he had a future at the club so he should stay, and he did. So far, unless Brewster has some injury I'm not aware of, he hasn't had a sniff.
Players at their age, with their potential, need games. They need to test themselves at a professional level in order to grow and prove their capabilities. But like it or not this mostly jars with what Liverpool want - to have and play the very best. If we're honest, developing these players with game time does not work with Liverpool's want and need to win titles - rightly or wrongly (and to a degree, I believe wrongly).
So I'm never going to blame players for making their way for the sake of their careers, for the sake of their footballing lives, rather then wile away critical years in the Liverpool system. Elsewhere they may well get more chance of actual games AND get the top class development - so for many, it's going to be a no brainer. It's hard to be a youth player in England, for various reasons (including the money, ironically). So I wish them all the best of luck. I think Kent is very talented, and perhaps we'll see him again in the League at least. As for Duncan, who knows.