Silly. It was a volatile situation. A lot of different things could have happened. Maybe Southerners would have realized how foolish the whole thing was and given it up. That was certainly what unionists hoped for and expected.
I would suggest that the secessionist leadership wanted a major break, a point of no return. They also wanted something dramatic to tip Virginia and the Upper South, which had rejected secession, into the secessionist camp. If the event was dramatic enough, it might bring the Border States into the Confederacy.
Also, Davis and his government were like the French Revolutionary leader who went running after the crowd saying "I must follow them for I am their leader." They had to get out in front of the hotheads in South Carolina and elsewhere and show that they were really running the show. They had to demonstrate their leadership and earn public support somehow.
So no, they weren't going to sit on their hands, and they weren't necessarily "manipulated" into anything either.
That is an interesting theory and is also probably a good stab in the direction of the truth. That does not preclude the possibility that Lincoln manipulated them too.
A lot of events are vector sums of numerous interacting factors. Both possibilities could be concurrently true.