Answering this question before anyone else asks, and the answer is the same as always: 30 days from Print Street Date.
Which means it will not be legal for Origins next week.
I don't know if CGL is planning to have any print copies at Origins for sale (I imagine they would like to, and *if* they can get any there, they will be a batch specially rush-ordered specifically for the con), but either way I cannot say whether it will be Missions Legal for Gen Con until CGL announces a Street Date. IF there are copies at Origins and IF the announced street date for Data Trails is within a couple weeks of Gen Con, I may allow it at Gen Con, but that's a very big if, and no one is allowed to ask me about it between now and then.