Thaddeus "Thunderbolt" Ross returns to the MCU in Captain America: Brave New World, his largest role yet. Ross has an interesting MCU arc that has largely happened offscreen. He debuted as General Ross in 2008's The Incredible Hulk and returns as the Secretary of State in 2016's Captain America: Civil War.

This timeline tells us that Thunderbolts* will happen either soon after the events in Brave New World or a little later down the road. Whatever the case, Congressman James Buchanan Barnes will be elected to office before he and the Thunderbolts become the New Avengers.