Its all just another publicity stunt probably. One insider says:

I don't think they're actually fighting but, instead, just promoting themselves. I also don't believe Haim pulled out of his own accord. He's had immigration issues for a while now and the reason they filmed their show in Vancouver was because Haim couldn't get into the US to work. Now he currently lives in Manhattan and Long Island and can't get back into Canada. My educated guess (and from my own research I've done regarding immigration thanks to Bush) is that the condition Haim was given in order to move into the US was to forfeit his Canadian citizenship. It's a stipulation for many people if they want to emigrate from one country to another. Most people don't get granted dual citizenship unless they have family or a job in another country and the dual citizenship allows them to flit back and forth. But the thing is, once you forfeit your citizenship, your home country (in Haim's case, Canada) sees that as a big eff you to them that he doesn't want to live there anymore and instead wants to live in the US (every country sees a forfeit of a citizenship as such). Now that he needs to get back into Canada to film, they're telling him eff you right back and not allowing him back in to work. It considered burning a bridge if you forfet your citizenship to a country because your chances of getting back in are slim to none. I don't think Haim would back out of his own accord.