Ever since Jeremy Renner got a new haircut, fans have been speculating on Hawkeye changing up his look for either Avengers: Infinity War or the unnamed Avengers 4. If these current rumors are true, it looks like Clint Barton will be donning the identity of Ronin, an alias that should be familiar to fans of Brian Michael Bendis' New Avengers.
MCU Exchange got the news from an unnamed source that also confirmed the appearances of the children of Thanos, as well as the new look Steve Rogers would have. Though an official report, image or trailer will be needed, the fact that the source got a few things right should make this a bit more legitimate than usual. If anything else, it would be neat seeing Clint use this identity and maybe even fight with a sword like he did in the comics.
As for the change in identity, it has been rumored that Hawkeye would go to a very dark place in one of the upcoming Avengers films, hence the new alias. It's not clear what these events are, but it could be related to his family, who we last saw in Avengers: Age of Ultron. While he does not have a family in the main comic universe, the Ultimate version did, before being killed by Black Widow.
Ronin has actually been the alias of numerous characters in Marvel comics, though Clint had it the longest. Maya Lopez, who Daredevil fans know as Echo, started out with the identity before handing it to Clint, since Kate Bishop was (and still is) using the name ‘Hawkeye.' The Ronin costume was used again in Al Ewing's Mighty Avengers run, this time by famous vampire hunter Blade.
Avengers: Infinity War is slated for a release next year on May 4. The unnamed Avengers 4 will show on May 3, 2019.