For non-Americans, there's an expression "Now that he's seen Paris, how are you going keep him down on the farm?" -- which should be self explanatory. So...now that Kuss has tasted what it means to win a big race, what's next? Will he just meekly go back to donkey duty riding 5 meters behind Jonas or Primoz on only the steepest pitches? Or will GC Kuss rear up on his hind legs and demand Giro leadership?
You've got a guy who, whether he was gifted a huge victory, still pedaled his a** off and with a decent team of his own can likely Top 10 any GT -- with some ITT upside, even. If I were Jumbo and there's going to be money on the table after the sponsorship shuffles, I'd sign him on a big 3-year deal, give him Giro leadership and some ITT training and say "be ready for the Tour as top mtn dom/semi-protected leader if things really go pear shaped." Worst case, you lock up the best climbing helper so other teams can't poach him.
If I were Kuss I'd demand that deal. (not sure when his contract ends, but he could always seek to renegotiate)