Not sure, that's where the bankers try to confuse us i guess...
what is your definition of inflation? Is it rising prices as the effect of an expanding money-supply, or is it just an expanding money-supply, wether some prices are rising or not?
As I understand: disinflation is a slowing rate of rising prices... it's not a slowing rate in expanding the money supply... so monero doesn't have disinflation, monero has a fixed inflation rate (as in can't be adjusted at will).
interesting discussion, but maybe off topic over here...
It is disinflation, if you look at a graph of Monero inflation rate it will look like this (except going negative aka deflation):
