According to a Reddit post, Twitter still scrapes a lot of personalized data from you even with all personalized ads settings disabled. Reddit user u/dangeredwolf says that he noticed this personally and soon realized that Twitter’s own privacy policies actually allows Twitter to use certain personal information. This includes what you say in Tweets, who you follow, your type of phone, where you are located, and what you click. It does make you wonder what personal information they are using when you opt-in!
Here is the Reddit post that explains it: