Yes, that jarred for me too. If there is an afterlife, I don't see why animals can't be there too.
I found the article interesting in the points it raised, but I think all your criticisms are more than valid. More of a conversation starter than an answer provider, though the idea that if there was a spectrum of other hominids, making a more graduated link from us to animals, that we (or some of us) wouldn't then see a divide is new to me.
My view is the longer I live, the more similarities I see between animals and humans. I think most animals are less complex than most humans, but when you consider a range of species - sheep, cats, dogs, some birds - you can see a lot in common with all, plus differences - but when you have a spectrum of animals like that, you can find comparisons to different human behaviours. As in some people resonate more with dogs, some with cats, so what I am trying to say is humans are more complex and variable, but if you consider multiple types of animals, you can find matches for different parts of the complexities and variability seen in humans.