Aircrew hypoxia recognition training is carried out in an hypobaric chamber (not ‘hyperbaric’). I do believe that it is not mandated in the training cycle of civilian pilots but it is a fact that hypoxia has been the cause of several civilian aircraft accidents over the years, costing hundreds of lives. It is conducted by the military in the UK and I have personally witnessed the effects on people training as aircrew, in the chamber. This training is not directed entirely at explosive or rapid decompression but also aims to help crews identify the insidious effects of system failures (oxygen regulators and other gas flow equipment) and reinforces the absolute need to keep a close eye on the cabin altimeter.
As a lifetime military aircraft engineer I may be overly sensitive to safety issues in any sort of flying (even a sim 
), but I make no apology for that.