I don't know if this will happen, since Will Smith was in "Suicide Squad".
I am legend was based on a book. Both the movie and the book ended with their main characters dying. So, a sequel would not be possible.
Since I don't know what it is, I'll say no.
You underestimate the greediness of Hollywood.
I know how they are. But they would need to pull another story out of nowhere to make a sequel that would not be faithful of the source material which would anger fans and may even have a backlash.
Another example is the proposed sequel of the movie "wanted", almost all characters died excluding the main character. They have tried to make a sequel since 2008, no success so far. It's almost the same situation than I am legend. No source material to use because the original stories were ended.
