Sunweb fckd up the situation with his knee big time, so staying there was not an option imho. If he had, chances are very slim that he would be in much better shape now. I think next year will be crucial. This year started with some bumps in the road, he had to postpone his season a few times, and then covid-19 happened. Let's wait a few months before writing him off.
I also can't take Kuss seriously as a GC contender for GT's yet. He's a great climber, either as a mountain domestique or stagehunter, he's among the best in the peloton. But so far he's done 4 GT's i think, and in each one, he had days were he was nowhere. Not even taking ITT's into account. I think Tom is still Jumbo's 2nd bet, as it is again clear that Bennett is not a GC leader.