I don't think the sideslip issue is relevant, for it assumes sideslip is present, which is not always true, and should not be present anyway in a balanced turn. If a little sideslip were present just prestall, then whether the aircraft rolled in or out of the turn would depend on the balance between directional and lateral (sideslip) stability.
Basically asymetric aircraft like the Harvard, with big props going round one particular way, would usually always flick in the same direction at the stall. Clean, symetric jet aircraft in a properly balanced level turn should stall without wing drop, but if there is yaw on, most likely because of a rudder input, then right rudder will depart you to the right, and vice versa.
In a descending turn, however, typically on finals, the slower inside wing will likely stall first, for the descent rate is producing a greater increase in alpha on the slow wing. This rolls you down and into the turn, with usually fatal consequences.
Dick W