Though cleaning your CPAP mask and equipment regularly is certainly recommended, it will not necessarily extend its life expectancy. The equipment manufacturers give a specific time frame that their products are guaranteed to work appropriately. When they give that time frame, that assumes that you will be doing the best to take care of your CPAP equipment by cleaning it regularly.
However, please do not let the fact that cleaning your CPAP equipment will not necessarily lengthen the time frame you can use it, detour you from continuing such a helpful and healthful habit. There are countless reasons for cleaning your CPAP equipment regularly. You are doing a great service for your quality of sleep and your quality of health.