We are in the "cool new toy, let's make slop" phase, but we already see how careful use of LLM's can make high quality code faster and better than humans can do solo.
Once they are over the learning threshold, every good developer I know actually likes to use LLM's, as they allow them to realize their visions faster. If Debian has a "no LLM" policy I think they will eventually only have devs who like to type.
I should add that of course the "immoral companies burning too much energy" argument has actual merit, no matter how useful LLM's are or aren't. But I don't think Debian should die on that hill, as the only difference it will make is that we no longer have Debian.