Why does it feel like that? WandaVision ends with an explicit tease that we'll see more of the kids.
In addition to what's noted above, Kang is appearing in Quantumania, and the only tie he really has to the Ant-Man mythos is his relationship with Cassie Lang, which was part of the Young Avengers origin.
They have introduced, at this point, every member of the original lineup other than Hulkling (and the second Vision, but given the differences between the MCU and the comics I expect we aren't getting him). I'm sorry, but that's not coincidental, it just isn't.