I dislike BJP propaganda as much as next educated person, but could it be just that if facebook stops sensoring BJP bots, they might provoke mobs to physically attack Facebook in India, and their employee's safety is important for them?
https://www.theverge.com/2020/10/27/21536149/ankhi-das-faceb...
This doesn't support the notion that they blocked even more fringe, and radical parties than BJP