No, the prosecution didn't ask for the maximum sentence. They asked for 9 years. The judge went with the maximum of 10.5 years anyway and was clearly influenced by the video, regardless of the family's intentions.
The ruling on this is here and is perfectly readable: https://coa1.azcourts.gov/Portals/1/OpinionFiles/Div1/2026/S.... The reporting of it has been abysmal.
Also note the obvious (but usually glossed over in news articles) fact that vacating the sentence doesn't mean he doesn't get a sentence. It means he gets remanded for resentencing (by a different judge, I imagine, but IANAL). Edit: Reading about resentencing processes it sounds like it could go back to the same judge, actually.