There is allot of fear mongering going on out there from trainers trying to scare you into hiring them, just stay calm!
No it is not past due to train your workers in WHMIS (2015). Ontario legislation was only updated effective July 1, 2016.
Trainers should, now and over the next two year transition period, be showing workers the old & new symbols, talking about the 2 new classifications as well as the old classifications, showing the 16 part (material) safety data sheets (SDS's)
In approx. 2 years (Mid 2018) all products entering the workplace should now be in compliance with the new changes, so we would them be tapering down showing the old WHMIS symbols and MSDS in WHMIS training.
In a nut shell thats what you need to know regarding changes in WHMIS Training.