Edison shocked animals with AC to disprove Tesla, trying to prove that DC is safer. That is fact. However, the article already states in the beginning:
Edison’s link to the death of Topsy the elephant may not be entirely grounded in reality.
As I posted a while back, this is a rumor that comes along often, The killing of Topsy was done by her handlers as they wanted to get rid of her, they could not handle her anymore after an incident with her original handler. The film of the killing was released by Edison films yes, but Topsy was killed a decade after the war of the currents, and Edison wasn't even in charge anymore of the company after the merger with General Electric. He wasn't present during the electrocution of Topsy, did not have any electric business anymore, and again there is no evidence whatsoever that he was involved.
I learned about the killing of Topsy because I am very interested in the life of Nicolai Tesla and his inventions. I dislike Edison because imo he did Tesla wrong, but I learned quickly that the most despicable thing attributed to him is very likely not true.