It would certainly help, would it be only trough saving mapower and ships from the disaster. It's still going to be a major defeat (the whole expedition is probably one of the best ancient equivalences to Sealion), would it be only morale and politic.
Nicias' reluctance to withdraw may be as well due to its ill-advised piety than to his fear to be the one blamed for the whole failure before Athenians that prooved having not that much issues about sending their generals down; but more importantly, Athens single-handly crushed any good reputation they still had among Greek cities with this joke of a campaign, and Sparta have certainly no issues pointing them as imperialists.
More over, I doubt Sicilians would just Athenian go their way : they might be unable to let them escape, but not without having send them back a taste of their own medecine. Having more ships, and less emergency on their side, Sicilians are going to take a part of the fleeing expedition down.
So, ITTL, what do we have? Basically the same situation than IOTL, albeit far less catastrophic : it might be enough to strive for another treve or more or less white peace with Sparta, preventing their catastrophic downfall. But winning a new war they had trouble managing some years before? I don't think so.