It's not the body itself, it's the embalming fluid, caskets, paints, etc that make up more mass that the body that are the problem. There's nothing fundamentally more toxic about the corpse of a human vs. the carcass of a cow.
Fair enough and a good point, but by the time a body is interred that's irrelevant. There's obviously a fair bit of viruses and bacteria that will thrive (or just survive if a virus) in a corpse but stuff like HIV, Hepatitis, Syphilis, etc are going to die with the body. If it's human specific, it's going to be too specific to survive much longer than the human did. There's stuff like MRSA (or any staph infection for that matter) to worry about but that's no different than the carcass of a cow.
The article seemed mostly concerned with the breakdown products of corpses sealed coffins, the coffins themselves, our implants and jewellery, and infection disease.
At a glance most of these seem like relatively easy problems to solve.