That does not actually say that Twitter will delete your account in any specific timeframe. Given the mostly-public nature of Twitter, it's sort of a moot poin

That does not actually say that Twitter will delete your account in any specific timeframe. Given the mostly-public nature of Twitter, it's sort of a moot point, but still. Ambiguity should be held against the drafter, especially in privacy policies. On Twitter's deactivation page, it doesn't say they'll delete your data either. "marked as deleted" is not the same as "deleted".