Does "Happy Birthday Diablo III" Buff affect Kadala?

So today is exactly 2 years since Diablo 3 was out. And because of that Blizzard gave us a nice surprise: a Happy Birthday Diablo III buff:

players who log in to defend Sanctuary this week will receive double Rift Fragments as well as a +100% boost to their chance to find Legendary items

So my question is: does this buff also affect Kadala? I tested it a few times, but the results are... confusing/complicated. It is based on a random chance, so before I could sometimes get 6-8 legendaries from 500 Blood Shards, sometimes there were none. I tried the same thing twice with this buff, but only got 3 legendaries (spent 1000 Blood Shards in total).

So could someone enlighten me please on whether or not this buff affects Kadala?

Solution 1:

The anniversary buff does not affect Kadala or Horadric Caches.

Source:

You're correct! The anniversary buff does not influence the Legendary drop rate from Kadala or Horadric Caches.

Solution 2:

A lot of people are speculating about this on the official forums; no Blizzard post on it yet.

The only fact-based speculation I have seen is in the comments in this Diablo Fans thread. Based on the code changes found for prior similar buffs, the thinking is that this new buff only affects drops from monsters/chests, not Kadala.

This seems reasonable to me, but until more information is out, we don't know.

On the bright side, the latest patch updated Kadala to at least give you items your class can use. I don't see any reason not to spend all your Blood Shards during the week of this buff, so I'd say go for it.

Solution 3:

Yesterday on a special broadcast Blizzard gave at twitch.tv/diablo celebrating the two year anniversary one of the devs confirmed that the buff does not affect Kadala, only world drops.