I suspect this is specifically targeting the Manischewitz - Welch's grape juice
Why would that be more of a target than any of the other kosher food sold by that group. After all they took over virtually all of their competitors throughout the years ever since they branched out of wine (and the bit of gefilte fish jars they used to sell). Itzkowitz, Hadar, etc. etc. were all taken over by the Herzog's companies. And even before that, they were taking over other wine labels (and importers IINM) that started to gain a foothold in the market (Rashi, Kesser, etc.).
I remember in the 1990s when the then owner of Haddar (or more precisely ERBA Food) decided to get into the wine business as retaliation for the Herzogs getting into his lines of business. Well, we know where that ended.