Great find :clap: Even if it does make a fool out of me :lol:
To be honest, it is just a mood board from early development, in the same way that what eventually became Thirteen had quary themes, racing themes, machines themes and several others. Air would have had several theme ideas before they settled on the oasis idea. This one was probably rejected because it did not fit with the style of the ride type, and because it would only really work if it was built over Nemesis, and even then was shaky in terms of plot. They were probably also worried about it being too similar to Oblivion.
And before anyone says it, they didn't reject this for the oasis theme because of 9/11. It would have been far too late to change in then and why should they have changed it? If it was built in America, maybe, and maybe if the theme involved flying into a building or something, but the oasis theme was chosen because that's the one they wanted to go with.
Air was never going to have a millitary theme, but it was considered before the deveopment really began.
Thats not entirely true though is it? Th13teen was born out of the dark forest mood board because that was the most popular option. If they had chosen racers theme we would have ended up with a completely different coaster, because the drop section wouldnt work at all on a racing theme.
Whereas with air it seems to be the other way around, they knew they were getting a flying coaster and had the choice of 2 themes (maybe more?) to fit around it - oasis and military. They chose neither and we ended up with a blue coaster on a bit of green land with some trees and a bit of fence.