Probably a diversification play and a play to see out bigger contracts. If you've worked in the FEDRamp space, you may be aware that Wiz (last a checked, a year or so ago) is one of the few and possibly ownly player certified to operate in FedRAMP Medium/High deployments operating with the technology it does (eBPF instrumentation).
Google has really been expanding into DoD lately. I think they're realizing it's a large part of why AWS is so big and Azure is still alive.