Read some of that google translated article but haven't reached much further. Some articles about primates and how they perceive death, some observed behaviour; posting it since they are related to the early humans and their possible cannibalistic tendencies (in the article about Porshnev's work it's part of the scavenging habits of theirs).
https://www.livescience.com/6335-chimps-understand-mourn-death-research-suggests.html
https://www.smithsonianmag.com/smart-news/gorillas-appear-grieve-their-dead-180971896/
So while it is known that primates sometimes consume deceased adolescent specimens, but it seems it depends more on circumstances. Furthermore they differentiate between the ones belong to their own group, and outsiders. And even outsiders aren't necessarily considered as a food source (the gorillas - the examples of the second article - are largely herbivores).
And one about Neanderthals and nidal and their burials, and possible burials.
https://www.sapiens.org/culture/hominin-burial/

The whole thing made me think if the notion that death is sleep roots in some taboo that we shouldn't eat the dead belonged to our group. "Stop my son, don't chew on grampa's toe, he is just sleeping!"