According to the blog post linked in the OP, the LLM-generated results were read, understood, and confirmed by the mathematician whose work they built on.
I notice a dichotomy here between people who care about results and people who care about process. The former group wants to use LLMs insofar as they can contribute to getting results. The latter group is wary of LLMs because they're more interested in the process and less interested in the results themselves. Needless to say, I think the former group is right, and I'm happy to see that mathematicians (or some of them) agree.