777x is pretty new and not actually in service for another couple of years. If we did get one, it would be well after it begins regular service.
That and all the 777x is is a 777 with bigger engines, 787 composites and a MAX Cockpit. Beyond that, most people will be satisfied with the PMDG 777 when it releases.
Also, i’d like to mention that nothing will be “Study level” as you will not be able to earn real world flight hours from it. The preferred nomenclature is “High fidelity” aircraft.
And yes PMDG has expressed interest in bringing PMDG Planes to Xbox. At least last i heard. They are still stuck with WASM Issues like most other devs…or something…