Heads up, Creators: On Dec 13-14 you may see a noticeable decrease in your sub count as we remove spam subscriptions. If spam is removed, you'll see a YouTube Studio alert: https://goo.gl/qGDBvX This should help give you confidence that the subs you do have are real fans!
Maybe because there are a butt-load of bots subbed to him during the subscribe to Pewd campaign? Thousands of them attacked the T-Series pages with identical comments attacking them.