My wife and I purchased a 2006 Uplander today. I went to unlock the tailgate to put some items in it and there is no key cylinder to unlock it from the rear!

Are they all this way?

I believe so. My '06 is like that. I think with the advent of power locks that might of been a reason for their demise. I had 2 Ventures( replaced by the Uplander) previously and I know for sure one had a lock cylinder in the rear, but in all the years of ownership, I never recall using it.