Believe it or not, customs isn't comprised of complete idiots. They don't need to look on the internet to see how ceed companies ships beans; that's their job and they do it every single day.
They know first hand from having found hundreds if not thousands of these packages how its done. Any customs officer can probably tell you off the top of their head ten different ways these are concealed.
On why the seizure rate seems to have gone up in Chicago, that's a good question.
I don't think this has anything whatever to do with WA State, since there is a customs office in Seattle and another one in LA.
Not sure if the mail routed to Colorado goes through LA or Chicago. Note that it by itself legalization in CO isn't a good reason to explain a policy change. CO doesn't need to import beans; they already have their own local ceed production, and clones are bought/sold openly there.
If it were a national policy change originating in Washington DC increasing priority of cannabis ceed seizure, you'd think seizure rates would have gone up everywhere not just Chicago. Maybe that's happened, but Chicago seems to be where all the problems are right now.
Its also possible (and IMO more likely) that there is just something unique to that office that's increased the seizure rate. Maybe they just got new equipment making it easier to find these, maybe they have a directive from a local customs administrator to seize them, maybe they've just stepped up enforcement/inspection in general, and increased cannabis ceed seizure is just a side result, or maybe one or more customs officers have made it a personal mission to find these (for whatever reason).
Given reports of personal "love" messages placed in individual packages I suspect its the latter.