Boeing could be a customer for procuring Wave solutions for their own internal network use.
Boeing is also one of THE largest gov't integrators. They don't just make airliners and military hardware, they also sell and install IT systems to very large gov't accounts. To guess, Wave is forming a relationship with Boeing, Boeing the integrator. These things take time. Imo Wave is forming relationships with numerous gov't integrators other than NCI. It's part of preparing to sell solutions to the gov't and military in increasing volumes.
NCI is listed #72 here (may not be quite up-to-date).