The Canadian M1 0w-40 had the older CF rating until quite recently. Nonetheless, it's a very dated rating, and while there are a fair number of vehicles on the road that originally called for CF, those tend to be older Cummins and the like. Operators of those vehicles were using HDEOs all along and most never would have considered M1 0w-40 even as an option, given that it's not a traditional HDEO. Additionally, here it has to be bought in 1 L bottles, and that gets a little pricey with a 15 L sump.
I have no doubt that M1 0w-40 would still work in an older diesel engine calling for CF in a 40 grade (whereas plenty of current 10w-40 and 20w-50 PCMOs here might be questionable). It just would not be even remotely cost effective.