They can only kill the license for future content, not for the existing content. And that would be a very clear sign that they're going to put up a paywall, and

They can only kill the license for future content, not for the existing content. And that would be a very clear sign that they're going to put up a paywall, and create a huge amount of pushback. But the most convincing argument that they won't put up a paywall to me is that there simply isn't enough money in it. You won't get enough people to pay for it, and it will cripple the amount of answerers.