Didn't see the Phoenix incident personally (I'm down in New Orleans) but I've been tracking similar triangular formation reports for a while now and I'm curious about a few things if you can remember.
Was the formation completely silent? And were the lights holding a fixed distance from each other or were they shifting position relative to one another - even slightly? That second detail is something a lot of witnesses miss in the moment but it matters quite a bit when you're trying to rule out conventional explanations like military craft.
Also what time exactly did this happen? I've noticed some of these triangular sightings cluster around specific windows in the evening and I want to cross-reference this against a couple of other reports from the southwest I've been compiling.