Previously the trains from containers at least has a small chance of being from before last region. No idea why that was changed.
Yeah, I sorta missed that change when it happened -- they did it rather quietly, it seems! Unlike P666 -- perhaps the only forum regular more grumpy and cynical than I -- I don't think this is a malicious change by Pixel. Indeed, it's partially remedying a frequent complaint, that crates are frustratingly random. At least now we know which region we're going to get!
Of course, for all other regions you do need to spend gems, which is unreasonable and unfair, IMO, but can't have everything...