I still think the MCU Pym will have a hand in creating Ultron, all I've got to go off is the teaser, but something tells me Hank Pym has his own agenda, he just felt a bit shady to me. In the comics I always got the impression he was very single minded and a little arrogant, and no matter what others thought, he would do whatever HE thought was best. It would be natural for that nature of someone's personality to progress to something a little more 'unethical' with age. I'm not saying any of this has anything to do with him creating Ultron, just from the descriptions of both movies I have read, we know Tony Stark will activate the dormant Ultron in the MCU, but it specifically mentions it's found in the ruins of the Chitauri invasion and that he didn't create it. Seeing as how Ant-Man wraps up phase 2, I think it would be cool if in Age of Ultron, they never find out who created the Ultron program. Then in Ant-Man, maybe drop a few clues as to it's Pym, or maybe just flat out reveal it, maybe just a file in his underground lab thing labelled 'Ultron Imperative' or something could suffice. We know Edgar Wright left this movie because Marvel wanted it to have more connectivity to the MCU, if it was just a cameo or Easter egg I can't see that being enough to leave a movie he has worked on for years, it has to be something with more ramifications, my bet, Ultron.