Well, they must have got it from somewhere, I suppose (if it is not just a mistake), but not quoting the source of forecasts is a serious omission by MI imo, especially if the forecast they quote (and expect to be beaten) is so much higher than the only one that is publicly available.
In the case of Small Company Sharewatch (from the same publisher?) I have found that occasionally they do quote eccentrically high and uncheckable forecasts which sometimes turn out to have been badly wrong.