The post is "Discord alternatives" so it strikes me as strange for only E2EE capable chat apps to be supported.

No, it isn't.

Dang moved all the comments from https://news.ycombinator.com/item?id=46979742 to this thread so now it's confusing.

Thanks, that was confusing. Anyway I loved your writeup, I hope alternatives will be built (alas, I've tried with Mattermost, but I'm not proficient enough in Golang to maintain a fork on my own)