Some countries, mainly European Union members, are beginning to mandate that new "street only" motorcycles imported into their countries must be fitted with ABS as standard equipment. Perhaps this ABS mandate is true for Canada as well? ABS has not been mandated for motorcycles sold in the U.S... yet.
It could even be a case of limited production capacity and availability of ABS components for these bikes (both the CBR300RA & CB300FA share the same ABS parts) from Honda's brake vendor Nissin, in which case those ABS equipped bikes will go to the ABS mandated markets first.
That said, I imagine that next model year American Honda Motor Co. will more than likely be offering the CB300F in both ABS and Non-ABS models for the U.S. market.