That's not how paraphrasing works. They probably intentionally held back from guaranteeing an interview, for various reasons. One that seems obvious to me is that with the bar set at "Claude Opus 4.5's best performance at launch", it's plausible that someone could meet it by feeding the problem into an LLM. If a bunch of people do that, they won't want to waste time interviewing them all.

Or honest?

You may want to consider the distribution and quantity of replies before stating that you WILL do something that might just waste more people’s time or not be practical.

The classy thing to do would be responding to every qualifying submission, even if it’s just to thank everyone and let some people know the field was very competitive if an interview won’t be happening.

So I like these public challenges, but as someone who set some public questions, ask any company who ran any public contest for their opinion. The pool is filled with scammers who either bought the solutions through sites like Chegg or sometimes even just stackoverflow.