Alaska Horizon (Horizon Air) is planning to resume Embraer 175 deliveries again in March 2018 according to Seattle Times. Deliveries were halted this past summer by outgoing CEO Dave Campbell due to a pilot shortage that has eased up. SkyWest Airlines filled the void for Alaska Airlines with their Embraer 175s.
The new Embraer 175s will gradually replace the Bombardier Q400 turboprops.