Nobody really knows, but we can guess.
[OW2] Balance Design Blueprint
And like you said, Wrecking Ball is the most difficult part of OW2 to balance.
Or rather, if they wanted to balance him so he’s good/great for the top 3%, and basically choosing instant defeat for about 90% of the playerbase. That’s relatively easy.
Or go the route I went, and just move him to the DPS role.