Huh, weird. The Twitch chats I hang out with and I tend to use "parasocial" as a term in which people develop a relationship with others that people haven't really seen or spoken to. I've seen them and myself use the term to talk about how chats have relationships with streamers themselves, which aligns with your definition, but I've also seen it used between Internet users that have minimal interaction with others aside from texting.

I've made friends online via Xbox that I have on other social media and that know my face/voice/background, but I try to secure more of my anonymity these days. I wouldn't consider those relationships as parasocial, but in some ways, depending on how the relationship evolves and grows or decays over time, I'd say they dip in and out of being parasocial and tangible.

Perhaps parasocial might be better thought of as a class of relationships people share that are digital and that don't manifest IRL in any meaningful ways (excluding face/voice/identity).

Maybe the idea I'm getting at here has a term coined for it already. I'd be willing to change my vocabulary if you suggest something!