Honestly, it's just a subtle misunderstanding due to how Anduril's product path blurs the lines between the products they sell now, and the structure of their company & goals long-term.
Long-term, Anduril wants to be a defense co. that bids for and wins contracts with the Department of Defense and challenges the monopolies of Lockheed Martin et al. To do this, they had to find an MVP that let them develop technology & make money in a way that could be leveraged toward that goal in the future.
Border security works well for this, because a lot of the software & hardware they will build here is dual-use for defense and border security. Furthermore, selling technology to the border patrol is probably the closest sales problem in the world to selling to the U.S. military - Same regulatory framework, sales cycle, Congressional lobbying landscape, even product review. It's a stepping stone to selling full-blown defense tech, hence the mish-mash of terms.
Border security works well for this, because a lot of the software & hardware they will build here is dual-use for defense and border security. Furthermore, selling technology to the border patrol is probably the closest sales problem in the world to selling to the U.S. military - Same regulatory framework, sales cycle, Congressional lobbying landscape, even product review. It's a stepping stone to selling full-blown defense tech, hence the mish-mash of terms.