I don't see that as fatal.
Looking at it by top 10 US companies by revenue, Walmart, Berkshire are probably only two that MIGHT not have DoD contracts. Amazon/Apple/Alphabet do for sure. CVS/UnitedHealth probably supply DoD healthcare, Chevron/ExxonMobil very likely supply fuel and Verizon supplies telecom links.
So if you are Anthropic, those 8 companies cannot use your software AT ALL. That's massive potential revenue to lose.
On the contrary, they are free to use it outside the defense supply chain.