The answer to why Ant-Man closes out Phase 2 could lie in a recent rumour regarding Ant-Mans placement in the MCUs chronology. A new rumor has surfaced that says Ant-Man doesnt tactually take place after Age of Ultron, but rather concurrently. Once it was announced that Hank Pym wouldnt create Ultron, fans wondered just how Ant-Man would tie into the rest of the MCU, but there is a theory regarding a Pym/Ultron connection, and if it proves true, then having Ant-Man and Age of Ultron occur simultaneously would make sense. With these two movies taking place, it would make Ant-Man perhaps the most connective of all Marvels solo movies yet. Especially if another rumor holds true