This is some truly exceptionally clownish attention seeking nonsense. The rationale here is complete nonsense, they just wanted to put "because AI" after announcing their completely self-serving decision. If AI cyber offense is such a concern, recognize your role as a company handling truckloads of highly sensitive information and actually fix your security culture instead of just obscuring it.
I mean it's not complete nonsense, but yeah, doing it for security reasons sounds like BS. I actually thought this was going to be about how AI makes it super easy for someone to steal all their code and fold it into their own competing project. I've seen a few open source projects get sideswiped by this, AI is pretty good at copying code (and obfuscating the fact that it was copied). I suspect that's the real reason but it doesn't sound as good. So they went with this half-truth.