I'm not sure I follow. Let's say that GLM remains the frontier of open source cyber capabilities because Kimi is nerfed. Your situation, and the situation of your attackers, remain exactly the same. You run GLM to audit your code, they do the same looking for exploits.

Let us say that un-nerfed Kimi was released, and it turns out to be at the absolute frontier of cyber capabilities, Mythos 5.5 level, a step ahead of anything else. What now? Well now your situation is exactly the same as before, just that auditing and hacking got more expensive. You run a Kimi security audit, they do the same to try to pwn you. However, now the cabal of Linux kernel defenders with secret access to Mythos 5.5 all of a sudden have no advantage, where before they used to have one. And even worse now they are in a literal race to be the first ones to find every bug that Kimi is capable of finding, and patching it yesterday.

So for you, this makes no difference in practice, your capabilities are not elevated, and neither are those of the attackers. The only result of the other scenario is an overall defender disadvantage.