Chatbots could deliver the personal connection to a messiah figure so many modern religious movements emphasize. I would be surprised if we don't see a church founded around the ramblings of a discarded bot in our lifetimes.
I think the more interesting (if highly unethical) thing would be to have a bot that is purposefully built to be a cult leader. Maybe train it on all sorts of scripture and see if you can get people to follow it...
Well we already have QANon, so I guess your idea isn’t so far fetched after all.
TempleOS,[0] by the infamous Terry Davis, featured a program called "After Egypt" that he would use to post text supposedly comming from God (or “space alian”).[1]