It's been almost a decade since I last looked at HuffPost, but what original reporting do they do? Back in those days, it was all opinion pieces, or piggybacking on other's original reporting.
If they don't do any original reporting, then dropping the opinion section doesn't contradict anything.
Good reporting costs money. A lot of money.
Also, don't confuse our prevailing normative social biases with a 'lack of bias'.