Yeah, in the Comics, it was Pym that built Ultron.
But in the MCU, it was Tony Stark and Bruce Banner. IIRC, the Ant Man in the MCU isn't Hank Pym. Pym was the original Ant Man from the WWII era who is passing on his suit to Scott Lang. That's not really a spoiler since the first trailer outright says it, haha.
So yeah, it's not even a Yondu situation, really. Pym is the team up, with likely Lang being the playable Ant Man.