So yokai here have their own society that's existed for a long time in hiding to protect themselves, and these yokai are being conflated together with the more recent "anomaly" type monsters, whether or not they actually have the same origin as the ones that are spawning and attacking places seems like it hasn't been solidly confirmed yet.
This whole creepypasta generation thing seems to be very actively targeting the yokai even when they're out in human form, so I don't think it's out of the question that the creepypasta machine thing is some new kind of exorcism tool that let's someone intentionally summon and control these human-made anomalies and someone is using them as a weapon against the yokai.