Yes, Marriott and the hotel will still receive something from someone staying even if they used a non-Marriott portal to make the reservation. But in most cases, Marriott and/or the hotel will probably make less than if the person made the reservation directly on the Marriott website. That is the reason most hotel chains (and even the airlines) try to steer customers to using their portals rather than 3rd party portals. Though different industries (airlines vs. hotels) and even different companies within a specific industry may use different approaches/tools to try to force or entice customers to use the portals that most benefit that company.