No, I don't find it strange that I want them to prepare for something they're not going to use normally, but agree it might be confusing.

For the actual positions I'm hiring for, nobody in the world outside our teams understands the systems. The candidates are going to need to work hard to learn what's going on when they start their new job. Some of it is going to be hard to do and not always a complete pleasure. Essentially I see it as a personality test that selects for the kind of people that figure out how to overcome technical adversity.

Willingness to do the work to be prepared and eagerness to dive into technical arcana despite it being not very easy-- these things are very relevant to the positions I hire for at Microsoft.