Bathroom Vent - exhausts into attic insulation - what to do today?
Many jurisdictions frown upon venting out of the soffit, particularly if the soffit is vented (perforated).  The rationale being that the warm/moist air from the exhaust vent will be drawn back into the attic.

I think the preferred location for the vent is through the roof or out the side of a gable.

Here's the way I vented a new powder room.