I just opened one and only got two items inside:

You open your Eighth Anniversary Gift Bag and find:

I'm confused? Is it up to three or is it three every time?

Are you sure the image just didn't load? That has happened to me a couple times.

XD I double-checked my inventory and turns out I got an item whoes image I've blocked XD So I did get a third item...:P Whoops! XD