Ad fraud research company Social Puncher said some popular users had gained back about a third of the followers they'd lost, but that the accounts disappeared again on Friday. They're not the only ones who noticed either, as Elon Musk tweeted recently about his fluctuating follower count dropping 20,000 or so in the last few days. It's unlikely that Musk had to purchase any fake followers, but those who did may have to get used to their smaller numbers going forward.
I think Twitter is deleting fake, scam or maybe even inactive accounts. My follower count decreased by ~20k over the past few days.— Elon Musk (@elonmusk) November 7, 2018