I haven't been following professional league as much as I used to, but is doublelift suddenly a great shot caller? I thought it was bjergsen as the shot caller before, and now it's sort of split between him and doublelift, but that doublelift has never been an 'elite' shotcaller. On CLG, it was all aphromoo, and still is as far as I know.
From the games I watched, it still seems like their top/jungle is their weakest spots but that was mostly a factor of getting outpicked/banned in a few games. The jayce pick looked horrible, not sure if I can blame hauntzer for that though. He's been solid all year, but maybe just he fails under the pressure of worlds? Biofrost has impressed me for the most part, and doublelift still has some insane late game plays but his early game is 50/50 against elite competition. Sven had some great games at worlds when they won, but he also did poorly in their losses. Not sure if replacing him or having another year working together would be better.
It's hard to say what TSM needs to do, because it takes awhile playing together to really build your synergy, so replacing anyone (no matter how good they are) will be a setback for awhile. But, they need to do it sooner rather then later if that's what they end up doing, so they have a full year to get a feel for any new players. Huni/reignover come join TSM?!? I can dream..
CLG: huhi and xmithie need to go eventually. Darshan had a bad split, from what I heard, but he still showed up at worlds and is still very talented. I don't think he's their weakest link, unless he started losing interest during the split and isn't practicing as hard these days. I can see that, and therefore he didn't 'get' the meta during the last split as a result. But, I'd also be willing to give him another chance if I was the owner. He fits the style CLG likes to play and the team has been built around what he can do for a long time. Replacing him would drastically change how the team plays, and Aphromoo might not be comfortable with that style.
C9: Obviously, Meteos is the weakest player, mechanically/individually. Whether he adds something intangible to the team, similar to what Hai did, is the only factor I'm not sure of. C9 is a very odd team, on their best days they look like they can beat anyone easily. In their bad games, they look like a challenger team. Whatever they need to do to get the 'good' C9 to show up more consistently is what they need, but who knows what that is exactly.