General New Collection???

[Deetee04]

Because I received a Mug from India and a Mug from Africa this morning by clicking my Adventure Buildings I discovered a new collection: Set of Mugs (number 178).
Since when do we have that and is it related to some event or sub-quest? It does not give a reward, only coins and experience and it does not show where to collect the items the regular way....

 

[Gt city]

Because I received a Mug from India and a Mug from Africa this morning by clicking my Adventure Buildings I discovered a new collection: Set of Mugs (number 178).
Since when do we have that and is it related to some event or sub-quest? It does not give a reward, only coins and experience and it does not show where to collect the items the regular way....

I found that too, got 2 cups today and was wondering, what it gives. Nothing so far, but might be related with future quest...