Nothing is certain, except for uncertainty; and if Blade ends up eventually flaming out, that would be the biggest example of suck since the Reaper strain threatened the world in Blade II.
2020 and beyond will provide interesting benchmarks of data to see where Blade is going, or even if Blade is going.
Let’s not forget, while Marvel Studios isn’t as erratic with its planning as DC was with projects like Cyborg and The Flash, there’s a possibility that another Inhumans-level disaster could be on the horizon.