If it turns out to be a good change or not is to be seen.
The half-full view is that the models are so good at finding vulns that if you plug them into your build-pipeline then the amount of new vulns introduced will go down towards zero.
The half-empty view is that we're now producing more junior-level code with less review, so everything will have more vuln, also it's cheaper and easier to find them so prepare for chaos.
Short term there is sure to be chaos either way as the models are clearly good enough to find all the old bugs, and not everyone has the resources or will to try to stay ahead of the curve like Mozilla is trying to do with their Mythos access https://blog.mozilla.org/en/firefox/ai-security-zero-day-vul...
There's a major caveat to the half-full view: You'll only stop adding new vulns that your model can find.
A threat actor with access to a better model or more money to burn on tokens may yet find more. Some of them have deep pockets, and not nearly every project will get the Glasswing treatment of free Mythos tokens.