Humanity has been completely converted, but some retained their minds through sheer will and god knows what. Luckily, they have a back-up plan. By making an A.I., they have a safeguard. If the ponies attempt to 'cleanse' their minds, they could simply give their consent and be uploaded, as ponies, but with complete minds an an ability to go back and forth using a robotic body. They get some dark visitors... (The Anthro tag is for the NewFoals who live in Final Fortress.