I would be shocked to learn if it weren't already happening, just frequently through several layers of obfuscation. But also, just generally. The NSA, to their minimal credit, has rather leaned in to making itself part of the OSS community by facilitating the development on a lot of the security and reverse-engineering products they use themselves. Unsurprising, considering the provenance of the internet, computers, and much of the underlying tech is deeply interconnected with the US DoD and NASA.

All that said, I do think a more open-ended "US public endowment for software development" is a great idea.