Well, some version of them are open source, which may or may not be what is actually running in prod. AFAIK the patch which made it obsessively bring up white South Africans was never published, and this algorithm repo went over two years between updates so it obviously wasn't tracking prod.
Nope, nor did that repo have the system prompts that brought is MechaHitler, nor the time earlier this year where it started injecting Trump into every completion.
The Grok repo is a smokescreen for deniability (just not particularly plausible).
I would be surprised if that line in the prompt caused it without the other thing they did just before mecha Hitler: Elon created a Twitter thread asking users to submit divisive politically incorrect facts for grok training. It was full of Holocaust denial and white supremecy stuff.