It's like how they made the Xbox, then the Xbox one, then the Xbox one X, then the Xbox series X. (Yeah there were other options between/simultaneous, but this sequence is a nice clean illustration.)
Yup. Could've been a future where they went from Xbox 360 to Xbox 720 to Xbox 1080 and so on. They probably got scared that some of the audience would have thought that the Xbox 720 would only do 720p, then crapped the bed.