The maps in Paizo adventures are not really compressed or shrunk.
Well, actually, they are. If you extract the images from the PDFs (I'm pretty sure they were JPEG - its been a while), you'll notice that the size is less than the size a raw bitmap image would be at that resolution and bit depth. That is the point of compressing them. The distortion in the extracted images blown to scale is the result of the compression.
I am not an expert in publishing or cartography, which maybe you are. But I am a principal engineer at a compression software company.
How they appear in the books is the size that the cartographer created them (and how Paizo commissioned them). In other words, what appears in print is about the highest resolution that the maps exist in.
I am pretty sure that Jared Blando is not creating these maps in a native-JPEG editor at the small size they appear in the module. I doubt any artist would. In many earlier modules, I have extracted and printed them at scale and they are still distorted, but look much better and are totally useable with miniatures. The images in this module are compressed to a higher degree for some reason, and this makes them look worse at scale - to the point where they aren't really worth printing.
Also, I seriously doubt Blando's contract with Paizo says "make us maps that look great small but crappy at scale". If you want to see what his maps really look like, go here, where he sells full-size versions of the maps he makes for another publisher (which Paizo should either let him do or do themselves by the way): The Red Epic
Thanks for submitting your speculation as if you really know what you're talking about, though. I always appreciate when people reply to my posts.