Check the bottom of the post. The tweets themselves are actual sentences from a book, not gibberish.
If you randomly start posting "Four score and seven years ago" and the rest of the speech out of order you are going to get flagged.
I used to build tweet spam bots, I am very familiar with how they get detected.
Instead, I was thinking that you might intersperse these in between your normal tweets, in coordination with the people you're communicating with.
I would have thought that the content of a tweet is quite low down on their detection list. IP address, user account, frequency of tweets etc would be much higher.