After Clint Barton's family was wiped out by Thanos, he ended up taking on a new mantle as Ronin, a vigilante who went on a rampage to wipe out those he felt didn't deserve to live after the "Snap." When we caught up with him in Avengers: Endgame, he was taking out the Japanese Yakuza, and it now appears as if they could factor into The Falcon and The Winter Soldier.
Reddit user /u/littlvinny has spotted some interesting additions to the Disney+ TV show's IMDB page which reveals that a couple of stunt actors have been added as a "Yakuza Bike Rider" (Leon Ngo) and "Yakuza Gang Member" (Kawui Joa). Both will reportedly appear in the third episode.
IMDB tends to be pretty reliable for casting information like this - as opposed to someone adding an A-List star as a character like Silver Surfer to an upcoming Marvel Studios movie - and this definitely points to there being a pretty noteworthy tie between Avengers: Endgame and The Falcon and The Winter Soldier as Sam and Bucky potentially attempt to clear up Hawkeye's mess.
Time will tell on that front, but photos from the set of the series have indicated that Wolverine villain Ogun will appear, and the Yakuza could very easily be affiliated with him in some way.
Time will tell, though it's no great surprise that The Falcon and The Winter Soldier will tie into the wider Marvel Cinematic Universe and deal with the aftermath of what happened in Avengers: Endgame.