Samsung has finally started rolling out the update to Android 9 Pie with the company's new One UI overlay for the unlocked Galaxy Note8, S8, and S8+ units sold in the US. This comes later than for carrier branded models in the States, which unfortunately has been par for the course for a couple of years now.
Anyway, if you have purchased an unlocked S8, S8+, or Note8 from the US, you'll be happy to know that a tasty serving of Pie is on its way to you. The new firmware version is N950U1UEU5DSC1 for the Note8, and it will require a 1.5GB download. The size is approximately the same for the S8 and S8+, and after installation you'll be on build G950U1UEU5DSC1 or G955U1UEU5DSC1, respectively.
The updates all come with the March 2019 security patch level, not April, but at this point that's still better than not having Pie at all. Obviously you should expect to see all the usual Pie goodies baked in, as well as Samsung's new custom skin - One UI - and all it brings to the table, including cosmetic changes and a system-wide dark mode.