We had solutions to Leetcode problems before LLMs, I don't see what's changed.
If your concern is about the value/signal of such an interview, it's the same as before regardless of how high or low you think it is.
If your concern is about cheating, without LLMs people can and sometimes do cheat in remote interviews but can't really do it in-person. Sure LLMs give you another method for cheating, I don't think that's enough to expect some huge paradigm shift in interviews.