It might be worth acknowledging people who have made it to #1, but a 7k club seems silly. Iso level 50 was a big deal since initially it was the max level. A new player would have their level be 25+/-25, meaning there is only a 5% chance of your skill being over 50, and level 50 meant there was only a 5% chance of your skill being below 50. This has a nice symmetry. Plus no one hit it for a really long time, and it's nice round number. 7k is not nearly as meaningful. It would have to be like 10k, or at least maybe 8k -- if you think "average" players are 4k (the first round number higher than the bots), then 8k is at least "double" that. But we don't really know enough about the rating system to say anything about that.