Even if we don’t see Hank Pym in Avengers: Infinity War, the fact that Ant-Man and the Wasp will take place in between the two big Avengers films certainly gives us the impression that the film will have it’s connections to them, which would seem to increase the likelihood that we’ll see more characters jumping back and forth.
There’s a better than average chance that we’ll be seeing more character crossovers in the near future.
Maybe the Hank Pym/Hawkeye moment is right around the corner.