"The democrats are/were historically the pro-worker party."

This hasn't been true for a few decades. they are now the party of the well educated professional class.

But he wasn't a "major player" - he was a press secretary. While we can assume he's a Democrat, the role has nothing to do with policy and more-often-than-not is filled by someone who's just good at being a flak jacket. Scaramucci was Trump's Press Secretary - he also worked for the Obama and Clinton campaigns.

Claiming his current worldview is in any way reflective of the Obama Administration is a reach... at best.

Scaramucci was his comms director. Big difference. The position of press secretary is one of the most important in the West Wing (It's been diminished a bit in recent years, but there is absolutely a policy component).