Yep, I thought that too. It's even more obvious when you listen to the audio of the trailer backwards: https://www.youtube.com/watch?v=ln5SOiyEn7w.
That music in reverse sounds like the great fairy theme to me... could that be the hand of the great fairy reaching out to him... did anyone check ganon's body to see if he had a bottled fairy? come on guys you need to loot the bodies properly!
Also the body is wearing Calamity Ganon's headpiece from the end of Breath of the Wild
Fancy hearing me on an amateur podcast with friends gushing over one of my favourite games? https://youtu.be/1I7JfMMxhf8