Possibly. Concept art we have seen for Avengers 4 could have been made during Avengers 3 concept art, due to some overlapping pre-production work. Hawkeye set photos show a somewhat different costume then the concept art, so the concept art should be taken with a grain of salt.
What do you mean? We've only seen the bottom of his costume (legs)
and it *** for tat matches the concept art. with the rest being covered. So its currently on point. Hopefully it all pans out with the Mk5