I do think that it's possible that they might show up as part of the 60th merchandise, with a slightly different look or something like that. MK has had the Mine Train popcorn buckets for a while now (before the carriage), but DLR is getting them as part of the 60th celebration (there might be some slight differences to make it look more like a diamond themed item). So it's possible that the carriage popcorn buckets will show up later. It's also possible that they might now show up in DLR for a long while and then suddenly make an appearance (e.g., DLR had the Jack Skellington coffin popcorn buckets for HMH for years before WDW got them, but they did ultimately show up at MK near the HM).