Well, Taylor seems to be releasing a single every 3 months ("Shake It Off" in August 2014, "Blank Space" in November, "Style" in February, "Bad Blood" in May, and now "Wildest Dreams" in August again), and she's already confirmed more singles, so it can be inferred the next single will be released in November again, most likely with a music video premiere/performance at the American Music Awards.

I can see this era ending in a similar way to the Red era, with her performing a ballad at the Grammys (probs "Clean"), and then quietly finishing the tour, all while recording at the same time. If the 6th single (most likely "New Romantics" or "Out of the Woods" - I'm hoping for the latter!) is released in November, it'll be ending it's chart run in February, and after the Grammys, there'll be be enough of a media downtime (at least relative to Taylor) from March to July for her to debut her electronic indie-trap masterpiece lead single at the VMAs without running the risk of overexposure!