Comment by staticman2

They can't call it the <something else> Box because they don't want people to think of it as a Microsoft Device.

Nintendo can go from Nintendo 3DS to Nintendo Switch because the brand is Nintendo.

Microsoft clearly considers the brand "Microsoft" to be poison ivy to gamers, and always brands their gaming hardware as "Xbox" as if that were the company name. Going to Ybox would kill their brand and put them back at square one.