Whether or not Howard reappears in the MCU in Guardians of the Galaxy Vol. 3 or another movie remains to be seen, though Lea Thompson mentioned a few months back that she was visiting Marvel to pitch a new Howard the Duck movie.
In Guardians of the Galaxy Vol. 2, Howard was seen on Contraxia at the same bar where Yondu and his Ravagers clan were hanging out.
In any case, now that we know that Howard could have shown up in Avengers: Infinity War, I’m concerned about whether or not the wise-cracking bird survived the Thanos snap.
When we first met Howard the Duck in Guardians of the Galaxy, he was imprisoned in The Collector’s collection on Knowhere, but he was freed from captivity when the Power Stone blew up the museum, though he decided to stick around and enjoy a drink in the rubble.