An NBA expansion is unlikely before 2025, when the league will re-discuss the tv agreement.
Per ESPN, KeyArena in Seattle is being renovated and is projected for completion in late 2020 or early 2021.
But Seattle may need to have a second new arena with the NBA team as the main tenant if the city wants to outbid other markets to attract a team, multiple ownership sources said.
Beyond expansion, Seattle could be a destination for a team that relocates. The Memphis Grizzlies are the most obvious candidate, but relocating would force Robert Pera to sell his stake in the team.