It's not different enough to bother publishing. In Horowitz/Volodos' cases, they drastically modified their Hungarian Rhapsodies. In Cziffra's case, he's just adding a flourish here and there that probably evokes to him the gypsy spirit of the pieces. He did it in Totentanz, the Hungarian Fantasy, and a few other Liszt works too. Within the extant text of the work (outside of his little insertions), as far as I can tell he's only doubling an octave here and there. In contrast, H&V add lots of new harmonies, counter-melodies, etc.
Currently Studying: Bach - English Suite No. 5; Beethoven - Op. 27 No. 1; Chopin - Op. 27 No. 1; Schumann - Vogel als Prophet; Alkan - Le tambour bax aux champs