if you submitted inland sponsorship and OWP and you receive AOR before your current visitor visa expires in Jan 2019, you will have implied status and don't need visa extension........however, AOR sometimes takes around 3 months to arrive and if for whatever reason your application is returned and re-submitted when visitor visa had expired your OWP will not be approved......although not mandatory, its advisable to apply for visitor visa extension......note: your inland sponsorship will be processed if you have status or out-of-status but OWP will only be approved if as at the time it was received your had status.