Earlier quoted context omitted.
Yes, the author says it's "the result after modifying (removed a blank page) and saving that same PDF in Preview." So it's not enough to just view the file in Preview.app I take it, but you need to save it out (which still shouldn't strip anything extra, obviously, but is not what I thought was being claimed).
So you are saying that they overwrote their file and are upset that the file they overwrote is different from the new file? This is insanity. Clearly a bug in AABBY that it can’t read PDF saved in the standard spec. PDF is not a bitmap, it’s a script like HTML or JS. People understand browser incompatibility but some how this is unconscionable.
Or even more accurately, that neither are using the same spec because PDF just isn't that standardized.