That could well be the case with the Fiocchi 9 x 25s with 9 mm Para headstamp. However, it is not the only instance of Fiocchi using the wrong headstamp on a cartridge. The very same 9M38 headstamp was also used on some 9 mm Glisenti ammunition, for which it is definitely not the correct marking. Since the Glisenti pistol and those carbines and SMGs chambered for the 9 mm Glisenti cartridge had likely been relegated to a “Substitute-Standard” position in the Italian arsenal in WWii, it is likely that only small lots of ammunition were needed for them, and it simply was cheaper and easier to use the 9M38 cases loaded to Glisenti standard, with lighter powder charge and truncated-cone bullet. That would increase the likelihood, in my eyes, that the 9 x 25 mm Mauser version with the 9M38 headstamp were made for captured or otherwise acquired (in small quantity) weapons. Of course, it is possible that the ammunition was used for both that purpose and for testing the Scotti designs.
It is not just the fact that Hungary was in full production of 9 mm Mauser ammunition (primarily in steel cases) by the time the Fiocchi rounds in question were made, but also that the box label for the Fiocchi 9 x 15 rounds is in the Italian language. Further, it obviously was a small-quantity run because the label is a reproduction of a hand-typed label, printed on the back of blue labels from 1939 intended for the 9M34 Pistol, caliber 9 mm Corto (.380 Auto), and glued to a prewar, anonymous, but known Fiocchi, commercial box originally labeled and intended for the 7.63 x 25 mm Mauser Pistol, a cartridge which has the same basic OAL as the 9 x 25 mm and which works just as well for the latter.
I am still not willing to discount that any of this ammunition might have reached Hungary. However, I have still not personally seen any convincing documentation of that assertion, and the other possibilities, including the use of an incorrect headstamp for purposes of convenience. and the case of the packaging leads me to give more credence to the opinions about its use that I have expressed. Everything, to me, points to small-quantity production providing an ammunition supply for a limited amount of weapons in use.