>>28040734TF2 remained relevant for at least five or seven years.
WoW's remained at least semi-relevant for ten plus years.
Starcraft classic/Broodwars is still played today, and Starcraft 2's still a thing.
Between what TF2 showed and Blizzard's track record, unless Sun and Moon remakes come out about ten years later, Overwatch is probably still gonna come up.