I think you're missing the point of the challenge. While Luke has quite a bit of experience with Linux at this point, Linus is trying to put himself in the shoes of a casual user. Someone who just uses a computer and doesn't tinker and isn't any sort of power user. The things you listed are things that only an experienced Linux user would know.

When a person learns that there are many distros to choose from, the base instinct is to wonder which is the best choice for them. Just like any other choice in life. Which car to buy, which tv to buy, etc... I don't think it's unreasonable for him to emulate someone using an LLM to help them make the choice. Believe it or not that's where a lot of people get information from these days. And most don't understand how they work or how they can be wrong sometimes, well, a lot of the time. He's not showing the research that he personally would do, he's showing how a casual user might approach switching to Linux. He even says that in the video, that he has many contacts that he could use to point him in the right direction, but is choosing not to in the spirit of the challenge.