>what confidence should I have that it is accurate?
They provide no example accounts either, so you will never know if it's accurate. It's entirely possible they deleted legitimate accounts of real individuals at the behest of the DCCC.
You misunderstand. The DCCC just informed Twitter, which they should have the right to do. Anyone should have the right to report accounts. Twitter alone made the decision to remove them.
Try not to set up thousands of automated accounts to express your opinion for you. You should be fine.