This isn't quite right as an exposition of Lewis's argument – it elides the distinction between the irrationality of "managing the news" and the way that (according to Lewis) the scenario pre-rewards an irrational choice. Evidential agents don't just "seem" to win – they really do win, because the scenario is set up to arbitrarily pre-reward them for being the kind of agents who one-box. Furthermore, it's claimed that the behaviour which is thereby arbitrarily pre-rewarded is irrational, because it amounts to managing the news.
The sense in which two-boxing is said to be irrational news-management is that doing so will give you evidence that you have been pre-rewarded, but won't causally affect the contents of the box – if you're an evidential agent, and have been pre-rewarded as such, you would still get the $1m if you were to miraculously, unforeseeably switch to two-boxing; and if you're a causal agent, and have been pre-punished as such, you would still not get the $1m if you were to miraculously, unforeseeably switch to one-boxing. The kind of agents that one-box really do do better, but once you've been rewarded for being that kind of person you may as well act contrary to your kind two-box anyway, despite the negative news value of doing so.
This isn't quite right as an exposition of Lewis's argument – it elides the distinction between the irrationality of "managing the news" and the way that (according to Lewis) the scenario pre-rewards an irrational choice. Evidential agents don't just "seem" to win – they really do win, because the scenario is set up to arbitrarily pre-reward them for being the kind of agents who one-box. Furthermore, it's claimed that the behaviour which is thereby arbitrarily pre-rewarded is irrational, because it amounts to managing the news.
The sense in which two-boxing is said to be irrational news-management is that doing so will give you evidence that you have been pre-rewarded, but won't causally affect the contents of the box – if you're an evidential agent, and have been pre-rewarded as such, you would still get the $1m if you were to miraculously, unforeseeably switch to two-boxing; and if you're a causal agent, and have been pre-punished as such, you would still not get the $1m if you were to miraculously, unforeseeably switch to one-boxing. The kind of agents that one-box really do do better, but once you've been rewarded for being that kind of person you may as well act contrary to your kind two-box anyway, despite the negative news value of doing so.