This was filmed before Blair Witch was even announced though

It's definitely inspired by the Blair Witch Project. Honestly, I think Ryan Murphy expected the sequel to the BWP to be a bigger smash summer hit than it turned out to be, hence why it's featured so heavily this season, but it's too late to really take it out. So instead of it being a focal point I think it's sort of an homage or decoration for the season. I don't really think it will be part of a larger storyline.

Yup! This year's influences seem to be coming from Paranormal Witness, Blair Witch, and Rob Zombie.
Less than forget. But more than begun.