The way in which we generate talisman pieces has remained the same since the first talisman set was released several years ago. We’re aware the random nature of this has been a source of frustration for people, so we have now made some changes to make this less frustrating (and to guarantee future uniform distribution of talisman pieces).
Previously, you could get any piece of a talisman on each roll. Previous rolls did not influence this whatsoever – each took place on their own. Going forward, talisman pieces will cycle on a global scale on a per talisman basis. What this means is if a person opens a cache for the Blackwave set and rolls for a piece of the canopic jar talisman, they will receive the first piece for that talisman. The next person who rolls for a canopic jar shall receive the second piece, and so forth. This is global and not on a per person basis, but should ensure there are always enough pieces to complete a talisman (assuming there are at least four) at any given time.
To be clear, the chance of getting pieces for a given talisman have not changed. You still have the same chance at getting rare pieces today as you did previously: you will now simply not get bad streaks of duplicates across multiple people.
This applies to all promotional sets. It does not apply to bashing only sets, such as the Dragon or Azatlan sets. It also does not apply to bonus pieces: only standardly awarded pieces will function in this way.