The first thing I did last night, was to change the options and see what data was possible (like how decchi's Azure Card could distribute Pokémon when gift type was changed)
Presently, I would be more inclined to believe that it was a real Pokémon gift, if the file had any semblance of Pokémon data.
It has messed up moves, messed up OT, and messed up TID/SID assigned to it. Every other field looks like junk data.
Frankly, I think the species data is also just junk data; the MysteryGiftEditor shows it's Zubat cause the junk data in that offset happens to coincide with a possible species ID.
Our situation is unlike the bad eggs obtained from Debug Ruby version, where the game actually gave you a pk3. pk3's in the save are actually encrypted.
Without the correct PID to decrypt it, the game would see it as a bad egg.
However, AFAIK pcd/pgt are not encrypted, so your "solution" does not apply here.
I believe that the reason we receive bad eggs, is because the pgt data is junk, and the bad eggs were merely following the structure dictated in the pgt.
I think the pgts are still worth archiving, just that I am not sure we can do anything more with them