i notice my follower count dropped here by about 4,000. i’m guessing there was some type of bot purge?

This is rolling out now! 

May see some funkiness for a few hours as we update the counts for all. users but by the end of the day, your follower counts will not include anyone who has been labelled "likely to be spammy"

Yep, exactly https://warpcast.com/v/0x5c4029e2

Yup. Zach beat me to it. 
Spammy accounts purged

Ok...that explains that...my (very meager) follower count dropped in half.

Yes, big 🤖 purge. 

Followed you to help add back one real person.

same happened with my account ...followers dropped...any idea about that