Dutch newspaper De Limburger reports, that Dumoulin's transfer might not be that complicated after all:
"According to Bobbie Traksel (Chairman of the Dutch Trade Union of Professional Cyclists (VVBW)), Dumoulin can just move, if he wants. "There is no cycling collective agreement at the moment and Dutch law always goes beyond the rules of the UCI."
Under Dutch law, Dumoulin is therefore an employee with a permanent contract and can leave with a notice period of one month whenever he wants. "Sunweb has a big problem and I am convinced that Dumoulin is very strong here. Just like everyone with a permanent contract, Tom just has a cancellation period. He does not need to put a transfer fee or similar on the table. I think Tom prefers to solve this nicely, but if they can't work it out, this is definitely an option, "says Traksel."
Promising, but it sounds weird to me, that Dutch laws could nullify the contract between Dumoulin and a German team.