Earlier quoted context omitted.
2nd deriv is negative and we're likely to overshoot, hence, the decision and article about it
2nd derivative being negative doesn't mean inflation is becoming deflation though, it just means that the rate of change of inflation is decreasing, but the inflation(and rate of change of inflation)itself will still be positive(unless I'm misunderstanding something, which is entirely possible).
Makes it hard to converse because _nobody_ is wrong here: i half-assed my way through an economics degree and know just enough to know OP is making a relevant comment, then confirm their comment: M2 money supply, is in fact, decreasing.