Now that the episode has aired, Jim has revealed why 'The Fault in Our Cutie Marks' aired out of the original order. According to Jim it was so there would be some CMC episodes in the second half of the season.
Also, in regards to the episode airing outside the country before the US, it wasn't their fault and, in my opinion, it was probably just other stations around the world following the original release schedule we had in the US since other countries are typically behind us. Plus DHX doesn't really have any control on when the episodes air, it's up to the stations after all.
So there you have it! The skinny on the mysterious episode.