Interesting but not as remarkable as the author seems to think, and certainly the New World parts of the maps are copied from European maps rather than being the result of independent and previously unknown exploration. The “island of California” was a mistake in much earlier maps, which got corrected in the late 16th century and then managed to sneak back into maps again in 1622.
Australia is a bit more interesting — Dirk Hartog had mapped the west coast in some detail just four years previously, though none of the detail makes it in here. Torres and Janszoon had also spotted the northern coast but not mapped it in much detail.
The map is also remarkable as much for what it’s missing as what it has. A pretty good depiction of the Gulf of Mexico, but Indonesia is a bunch of random blobs, and... just one island of Japan?
If you look at a large number of historical maps, you’ll notice that each mapmaker / each country had their own errors (sometimes trivial spelling mistakes, or pairs of cities with the labels swapped, other times comically wrong coastlines or even stuff like California-as-an-island) which persisted for centuries after corrections had been made in maps from other makers. If you compare the errors you can figure out pretty easily which previous map “lineage” was used as the basis for any particular map.
Australia is a bit more interesting — Dirk Hartog had mapped the west coast in some detail just four years previously, though none of the detail makes it in here. Torres and Janszoon had also spotted the northern coast but not mapped it in much detail.
The map is also remarkable as much for what it’s missing as what it has. A pretty good depiction of the Gulf of Mexico, but Indonesia is a bunch of random blobs, and... just one island of Japan?