In John Wick 2, the Payday Gang will show up in a cameo.
It's only fair, after all, since he showed up in their game. And much like him, the Payday gang is characterized largely by their Undying Loyalty
to the ones they love.
- They could cover him as he escapes from several Mooks, or he just happens to wander into one of their heists and they stop to help him out. Or they show up in the finale.
- Better yet, part of the movie is them doing a heist to help Wick out as a favor. They are the type to help one of their own, after all.
- The true ending of Payday 2 all but confirmed that the gang went separate ways and Bain is the President of the United States.
The Tarasovs were never very well regarded by the Continental if not the rest of the criminal underworld, as well.
The staff of the Continental tell John where Iosef's going to be (the Red Circle club), and where Viggo is going to try to make his escape from John's grip. They bent their own rules almost to the breaking point to help John kill them, and do so with apathy if not pleasure. Given that the Tarasovs most closely resemble a real-world criminal organization, compared to the Continental and High Table's exaggerated power and reach, the Continental may have just been looking for an excuse to get rid of them. John's revenge quest just dovetailed neatly into that.
- It's also just a matter of the Continental just liking John a lot more that they may bend (but not break) some of their rules. However the Tarasovs putting out a large bounty and willing to double it to have someone break Continental rules may have also allowed Winston to turn a blind eye later on. Even if Perkins had killed John in his room the Tarasovs might have found themselves excommunicato since they put the bounty out specifically to kill inside the hotel. Chapter 2 implies that the Winston runs the bounty system he would have known exactly why Ms. Perkins broke the rules
Iosef Tarasov lived abroad until recently.
Viggo points out that Johns impossible task took place so he could retire, five years before the start of the film. The Russians took over New York because of whatever happened that night but it was most likely a very long drawn out process so Viggo probably had Iosef living overseas possibly going to school in England for his safety until he had a firm control over the city and it would be safe to bring Iosef back to America. This would explain why Iosef has a British accent, why he has no idea who John Wick is, and why he only seems to run basic tasks and low level murders for his father (He was sent on some task to "silence" someone and was returning from it when he met John, but if the person was that important Viggo would have contracted the hit out to a professional). He is only just starting to work his way up the chain when the first film starts.
Daisy faked her death as an elaborate plot to get John working again. We're through the looking glass now, people.