Simply put, no, this won't happen.
I've been a player for a very long time, the last time I've seen an item for "free" was years ago, probably 2011 or 2012. You can't just make the entire world of Graal have free items, read what Green posted above for example. It would also be incredibly unfair to those who paid actual money, or farmed their way to earn these items. If anything were to happen, they'd release a hat that costs 1 Gralat, and keep it that way for a week or so while it's available to purchase, but as meantioned earlier, this hasn't happened in years. The closest it has come to that is the 500 gralat hats we've seen recently, or the current pins in the Onnet store for example.
Hopefully you can see and understand why this won't ever happen.