This doesn't mean he had to pay them. It's a settlement so both sides agreed. It's hard to imagine a situation where Nerlens (or his lawyers) would decide to lose money instead of continuing the suit so they could get a ruling from a judge or jury.
More likely is that Klutch agreed to pay him a settlement of X dollars in mediation, to avoid going to court, but got to subtract the fee that Noel had refused to pay before.
The withdrawal is standard, it's always what you have to do to get the money. A judge already decided the case had merit, since Klutch would have tried to get it dismissed as one of the first steps.