A raccoon will not be grabbing a chicken thru the roof of the run. There is no reason why a chicken would be within grabbing distance of the roof of a run, especially during the prime raccoon/ground based predator hours. We are talking about a roof, not a wall at ground level. Since they say their goal is to keep birds in and hawks out, the wider spaced and thicker/heavier wire is the way to go for at least 4 reasons I can see. First, thicker wire will last longer. Second, price will be the same, if not slightly cheaper. Third, easier to work with. Fourth, leaves and other stuff falls thru a lot easier, so makes maintenance easier. Also snow....they live in Oregon, so most likely get a little snow. Or a lot. Depends on which side of the mountains. A roof of hardware cloth will hold snow like a sold roof would. But will be weaker.
I echo what
@imnukensc said in their post in regards to hardware cloth being fabulous in general, but not the needed/prefered choice for a ROOF to a run.... "I agree, but that's not what the OP asked about."