The first season of "Charmed", an American supernatural drama television series created by Constance M. Burge, premiered on October 7, 1998 on The WB. Airing on Wednesdays at 9:00 pm, the season consisted of 22 episodes and concluded its airing on May 26, 1999. Paramount Home Entertainment released the complete first season in a six-disc box set on February 1, 2005.
The language spoken in "Charmed" is mostly English.
The statement is definitely correct because "Charmed" is an American show marketed towards American audiences. Thus, the language must be (mostly) English. The system probably did not take account to language because it is not mentioned in the agent.