That being said, to outright ban a technology in 2026 on pure "vibes" is not something I'd say is reasonable. Others have already commented that it's likely unenforceable, but I'd also say it's unreasonable for the sake of utility. It leaves stuff on the table in a time where they really shouldn't. Things like documentation tracking, regression tracking, security, feature parity, etc. can all be enhanced with carefully orchestrated assistance. To simply ban this is ... a choice, I guess. But it's not reasonable, in my book. It's like saying we won't use ci/cd, because it's automated stuff, we're purely manual here.
I think a lot of projects will find ways to adapt. Create good guidelines, help the community to use the best tools for the best tasks, and use automation wherever it makes sense.
At the end of the day slop is slop. You can always refuse to even look at something if you don't like the presentation. Or if the code is a mess. Or if it doesn't follow conventions. Or if a PR is +203323 lines, and so on. But attaching "LLMs aka AI" to the reasoning only invites drama, if anything it makes the effort of distinguishing good content from good looking content even harder, and so on. In the long run it won't be viable. If there's a good way to optimise a piece of code, it won't matter where that optimisation came from, as long as it can be proved it's good.
tl;dr; focus on better verification instead of better identification; prove that a change is good instead of focusing where it came from; test, learn and adapt. Dogma was never good.