If the former POD, Cicero is still alive. If the latter, he's dead. This would make a difference, methinks.
Maybe. Cicero certainly has some pull but how much pull at this point?
Cicero was certainly one of the most senior consulars, but neither Cassius nor Brutus were willing to be puppeteered by him. Additionally, Lepidus, Octavian, Ahenobarbus and Sextus Pompey would be around to demand consulates, proconsulates, legions and vast provincia.
Well if the Liberatores win at Philippi, Octavian's a dead man. Lepidus, depending on his next move, might also be a dead man.
Lepidus was brother-in-law of both Brutus and Cassius. Antony's death would free him from being bound to him and allow him to throw all his authority and prestige as a surviving Caesarian leader (leader but not one capable of heading a faction of his own) behind the Liberatores. Or perhaps he might act to intermediate between Octavian and Senate with the Liberatores.
Octavian would still have dictatorial powers sanctioned by the Senate and provinces and legions at his back to provide him enough chips with which to barter with the Liberatores. For one, he could reconcile with cousin Sextus, legitimize the latter's position and take down the Liberatores in a year or two's time.
On the long run the Republic is dead anyway.This would mean the long-term survival of the Republic but perhaps not so much of Rome itself. Two PODs to achieve this are that Antony is also killed or that the Liberatores win at Philipii. What I have suggested are merely suggestions. What are your opinions?