For instance, she could have become a metahuman advocate, having been fueled by her father’s years-long hunt for Banner and his recent anti-hero legislation.
Plus, an appearance from her could also lead to a reunion (and potential reconciliation) between her and the returning Banner.
This would make her a key ally to Jennifer Walters and bring her back into the action in a unique way.
If Betty returns, she could still be a scientist, but maybe she could be repurposed (like her father) to better fit into the narrative.