And then also how is it bridged to glowie?

Just like how you have "newfag" and its more civilised equivalent "newbie" (though the two terms are more independent from each other, the latter is older).

where did you see that and what makes you think this association extends into the wider world?

Youtube, 4chan and similar shithole sites that directly followed Terry Davis, and which initially formed and adopted the lingo. Many such people are also in the circles that focus on privacy, distrust of the state and big tech companies bordering on paranoid, etc. (4chan's /g/ in particular)

I have seen the old r/waterniggers

It was just r/waterniggas. And IIRC it wasn't generally meant to be racist, so the shift to r/hydrohomies was tolerated. They got banned just due to the name, not behaviour of the users. It's really not equivalent to people laughing at and making memes out of a schizophrenic man spouting racism.