I was browsing the rewards section looking for upcoming rewards and i found a new 3 month Game Pass Ultimate reward. To qualify you need to take the "Xbox Essentials Accreditation / missions" . It was showing with a purple banner across the top of the icon on the home page learning paths. Took a couple of days to be allocated to me but I was able to redeem the reward credit against another 3 month GPU code.
https://expertzone.microsoft.com/about
This is the site. you will need to be either a retail (Microsoft store, staples etc) / Enterprise/ Partner employee to be eligible for rewards as these are courses designed to inform on how Microsoft products fit customer requirements.