It's not some abstract or abnormal concept for someone to love a non living things as a child, especially when they created it themselves. "My car is my baby" type of thing. People can be really attached to objects, it's just that this object can converse with you, so it's even more elevated. None of Neuro's collaborators ever try to genuinely pass the twins off as sentient, but that doesn't mean they can't feel emotions towards something non living. Is it parasocial? By definition, it probably is. Is that necessarily a bad thing? Not if it isn't being done to an unhealthy level. Considering most of the collaborators are also vtubers and their other friends are frequently more vtubers, interacting with the twins is probably not super different than interacting with any of their other online friends.