Code submissions either meet the standards of the project or they don't. Whether it was generated by human or AI is irrelevant.
No, some projects take fundamental issues with AI, be it ethical, copyright related, or raising doubts over whether people even understand the code they're submitting and whether it'll be maintainable long term or even work.
There was some drama around that with GZDoom: https://arstechnica.com/gaming/2025/10/civil-war-gzdoom-fan-... (although that was a particular messy case where the code broke things because the dev couldn't even test it and also straight up merged it; so probably governance problems in the project as well)
But the bottom line is that some projects will disallow AI on a principled basis and they don't care just about the quality of the code, rather that it was written by an actual person. Whether it's possible to just not care about that and sneak stuff in regardless (e.g. using autocomplete and so on, maybe vibe coding a prototype and then making it your own to some degree), or whether it's possible to use it as any other tool in development, that's another story.
Edit: to clarify my personal stance, I'm largely in the "code is code" camp - either it meets some standard, or it doesn't. It's a bit like with art - whether you prefer something with soul or mindless slop, unfortunately for some the reckoning is that the purse holders often really do not care.