For all the sites I see none of these things matter, domain age etc., just don't seem to be factors. The only consistent thing I've seen is that all my google analytics sites were hit, while the ones that didn't have it weren't touched. They had no movement whatsoever. I'm not saying it's a factor...it's just the only thing in common I can see. Of the 3 that were not hit, 1 was super high quality, and 2 are what I would consider lower quality. The ones in google analytics that were hit, I would consider 4 very high quality and another 4 to be low quality. So who knows.