It's not solving the Millennium Prize problem, which is to show that Yang-Mills theory without fermions makes sense and has a "mass gap", meaning that it predicts a glueball of some nonzero mass. But proving Yang-Mills theory makes sense is a big first step. And getting fermions into the theory is also good.
Note how they're working with all the key bigshots in this particular subject, trying to curry favor with academia:
https://openai.com/index/building-scientific-understanding-with-academic-communities/
Better than ignoring the practitioners altogether, like they did in the big theorem dump.