To answer your last question first, because Wingert in particular clearly had value for RSL, to the extent that NYCFC gift-wrapped him for them and asked other teams not to claim him, meaning he had value for other teams as well. If international spots truly grow on trees like some point act like, then it should be reasonable to expect NYCFC could receive a "trivial" benefit for providing something of value.
More broadly, we don't know the details of either of their new contracts. Posters on this board assume the contracts are lower, because we have a low perception of the value of these players. Until the players's union releases salaries, it's all speculative.