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!
and now you'll be under 1000 subs again... like many others who've just met the requirements. they had this planned for quite a while i reckon.