The fact that both of these characters share the same moniker in the comics and they're making a Black Widow movie post Endgame but takes place post Civil War, I'm thinking that they are setting up for Yelena as the new Black Widow
It would make the most sense and finally put to bed any question of them resurrecting Scarlet's BW. She dead and gone, but this way we still get a BW on the team/in the MCU.