My initial assumption was they got an intern to do the calculator, and he didn't know about the cap.

However, I've talked myself into the idea that it's possible. I said earlier that nothing had changed to make raising the cap necessary, but I realized I was making the unwarranted assumption that UA's primary business is to be a transportation company.

Upon further reflection, UA's clearly positioning itself as Chase's marketing arm. And that means there is a reason to remove the cap -- if you have a 1K who spends an average of $8500 per ticket, there's little incentive for them to get a United card. Removing the cap makes this lucrative customer available to Chase.