I just got my first box of Vandoren V16 3.5 reeds. The package was smaller than the other vandorens. When I opened it, i saw that the reeds were not in the plastic "optimal humidity" packaging.
Another things is that on the bottom where it says "Suprieure Vandoren Paris France V16 3 1/2" the printing is very blurry compared to the other Vandoren reeds.
The reed holders seems to be different as well.
Having no experience with the V16, I can't really tell if those are fake or not, but they play just fine.
[I attached images, hopefully they work]