Both the Avant A6 and RS6 are expected to arrive next year in 2020, probably alongside the new RS7. The previous two generations of the RS6 Avant have never been offered in the US market, making them tempting pieces of forbidden fruit for American car enthusiasts.
American buyers prefer SUVs to wagons, although the wagon segment was successful in 2018 thanks to a flood of new models. While BMW has not built an M5 wagon since 2010 (only in Europe), Mercedes currently builds a wagon version of the E63 AMG for the US market. Now the E63 could be getting some fierce competition.