Yes you can have it centered. The plaza is 12 spaces wide so the door to the Residents Services building will be at spaces 6 and 7.
So it would be like:
x x x x x o o x x x x x
Where the x's are spaces and the o's are where the door to the building will be when the tent is upgraded. The initial tent won't be lined up so you will have to use weeds or another resource to count the spaces if you have trouble visualizing or want to make 100% sure.
I reset approximately 20 hours to get this setup a week or so ago, however I was also being fairly picky and resetting for airport color, fruit, river exits etc. and I came across many that were set up this way.
Just note that when the maps are shown to you that the location of the plaza will be slightly off to the left of the airport and you will likely need to pick the map and fly in to verify its location since it's difficult to eyeball.
Feel free to PM me if you want to visit or have any more questions since I went through this process recently!
Edited to add: The plaza doesn't change sizes when you upgrade. It's just misleading because the tent is aligned to the top right of the plaza when you first start the game so it can trick you. My first island had the tent and airport aligned, but not the center of the plaza where Resident Services ultimately is.