You're unlikely to get a formal explanation of the decision. Twitter is maintaining its policy of declining comment on official accounts. However, Recode tipsters understand that this is a permanent suspension -- that is, a ban. Stone has a long-running history of launching personal attacks against those who challenge the politicians he supports, often using vicious (and occasionally bigoted) language. He wasn't about to take CNN's revelation (which has since been supported by Reuters and NBC) lightly.
Source: CNN October 28, 2017 23:37 UTC