Rush was definitely not offered for tonight. I hit refresh on my browser right at noon, and it was marked as Sold Out. I also had trouble with rush earlier this week: I kept being told that rush seats were available but when I attempted to add a ticket to my cart, the system either crashed or told me my cart was empty. I tried this for like 20 minutes before rush was officially marked as Sold Out. That day, I was on my phone on the subway, so bad service might have been part of the issue, but I got the sense that their website was being dysfunctional (I've snagged rush before on my phone on the subway).
Their rush page does note that they don't offer rush for every performance and that they reserve the right to change their policy and/or end the rush offer at any point. I also don't think it's ever been 200 seats... maybe 20? In any event, I've never had trouble getting rush in the past.