I hope he doesn't. I think his ability at CM for us is rather exaggerated; he just seems to lack some sort of dynamism - that game at Stoke down this final stretch of the season sort of showed some of it. He doesn't have that dash in the first few yards or the turning quickness to get out and quickly press and close out an opponent in the open field (versus on the side where he has the line as his aid). I think we already have better options there in Henderson (if fit), Wijnaldum, Lallana, Can, etc. and I think Milner being switched to LB has as much to do with Moreno's shitness as with Klopp's assessment of how to best use Milner in this team.
Lately, I've been thinking that Milner might be a better option for us at RB in games against the sides that sit deep. His effectiveness on the left is diminished by his need to cut back to his right foot and/or use his weaker left, and our attacking momentum often takes a hit when he does that - about as much as it does when a ball gets played to Clyne and he gets into the final third and turns poo. On the right though, with his ability to put in a better and earlier cross, Milner would have the edge over Clyne. With Mane seeing the ball often, Milner should still get the space, touches and involvement (as he does when Coutinho plays ahead of him at LW), while the momentum of our attacks won't need to slow down too. Against the stronger teams, I'd want Clyne back in at RB because he has the motor to go up and down and keep up with pacy wide forwards better than Milner, but against the deep-sitting teams, I think Milner can offer a greater threat for us.
Of course, Trent is another option there at RB. I'm unsure if he'll eventually be a RB or a CM for us instead (he played both positions for the U18s and U23s) - there was a league game when he came on as a sub at RB or RB, and ended up drifting into the middle quite a bit and looked really good there. The defensive side of his game is still pretty unpolished, but on the attacking side, his pace and quality with the ball in the final third is quite exciting.