According to the BBC’s David Lee, the Twitter account purge will take place on December 11th and include accounts that have been inactive for 6+ months.
“Inactive” refers to accounts that haven’t logged in for the past 6 months – so an account that doesn’t engage with anything is still considered active as long as it has logged in.
More on Twitter’s action on inactive accounts: The company is clawing back accounts that have been inactive for more than *six months*, which is likely a very large number. Inactive = user hasn’t *logged in*. Seeking clarification on what happens to useful/fun bot accounts.
— Dave Lee (@DaveLeeBBC) November 26, 2019
Twitter is sending out emails to owners of inactive accounts to notify them of the pending deletion, which will give them an opportunity to log in and save their account if they wish to keep it.
It’s unclear at this time what will happen to bot accounts that are never actually logged into by a human user. Presumably, they will avoid the chopping block as long as they’ve been publishing tweets.
For what it’s worth, an owner of several bot accounts mentioned that he hasn’t received email notifications about the accounts being deleted.
So if there’s an inactive Twitter account out there that has a username you’re after, you may be able to claim in on December 11th. But make sure to act fast.