Might be true.
I can confirm they put the English version of dawnguard on the italian Marketplace. It was available last night, i downloaded it, i didn't have much time to test it, and my charachter is in Blackreach right now, so i didn't want to go out and start the DLC, woldn't have been good roleplay.
Even so, i found some "dwarven bolts" in loot, written in english, therefore looks like it's working -touching wood-.
What i wanna say is: looks like Bethesda did it, where it was possible; they put the English DLC on some FIGS marketplaces. There's really some problem with austrian and german marketplace that prevents them from putting it there...
Could be perhaps because of the USK and PEGI stuff. But still that ain't making any real sense since ^^ PEGI classified the game as 18+ and in Germany it got classified as available on 16 years accomplished....
Which means actually, they could also put up the english version of skyrim DLC to the market, since the content isn't much more gore than its german version.
XD all I can say is that this world is becoming [censored] up, with all those version, giving upon us restrictions where or whatsoever we should buy.
This ain't really a free market anymore, which I find a real pity. I know ^^ it may just be a game, but lets take this as a start into a more gloomy future for gamers and other things.