Throw is the vertical part of that movement. A fault can place reservoir against seal and trap a column, or it can break the seal and leak. Which of those happens depends on the rocks it puts side by side and on the material smeared into the fault zone, not on the mere presence of a fault.
A fault picked on seismic has a position uncertainty that matters when a well is aimed at a block next to it. In a wellbore, a fault can also be a loss zone or a stuck-pipe risk while drilling, which is a different problem from whether it seals at geological time scale.