Since the release of the new Hearthstone expansion "Journey to Un'Goro", there have been a number of threads on Reddit that reported a possible bugged card distribution.

In the last expansion "The streets of Gadgetzan" the frequency of the 3 faction cards was set too high in the first few days. As a result, the players received an unusually high number of duplicate cards. To compensate, Blizzard gave all those affected an additional 33% card package. So if you opened 50 packages, you received 17 new packages as replacements.

This Friday, after the publication of Reise nach Un'Goro, many customers now had the impression of receiving an extraordinary number of duplicates. Whole r / Hearthstone was full of threads on the subject and the assumption that there is also a bug here. The development team at Blizzard responded immediately and examined the frequency distribution.

Official statement from Hearthstone developer Blizzard

The following statement was then published by Daxxari to the American community manager:

We have seen a number of posts from our community today regarding Journey to Un'Goro packs and the possibility that they might be distributing an abnormally high amount of duplicate cards. We want to assure everyone that we have looked into this concern and have found that Journey to Un'Goro card distribution is working properly, both at a per card and per rarity basis, and is consistent with previous Hearthstone releases.

Thank you for bringing this to our attention. We really do appreciate all the feedback, even when related to possible bugs or concerns around the game.

Roughly translated: We have seen the community's complaints about a possible abnormally high duplicate rate. Upon reviewing the Travel to Un'Goro packages, we found that the drop rates are as intended. The frequency per card package, as well as the individual card frequencies, are perfectly fine and comparable to previous expansions. Still, we thank all of our concerned customers for the feedback and efforts at Hearthstone.

So "unfortunately" no bug and therefore no chance of additional free card packages. People tend to recognize supposed patterns by chance. Probabilities as in this case cannot be found in 10, 100 or 200 packets. To do this, you have to have values beyond 10,000 packages in order to be able to carry out a statistical analysis. Only Blizzard has such amounts of data in Hearthstone and you have to trust their statement.