It doesn't change anything. Carthage's lost everything minus its possession in North Africa and if the Romans don't respond immediately with another army, which they will, Masinissa and the Numidians will attack.
I think that Rome will not répond with another army. The majority in the Senate was reluctant to Scipio's plan. So if his plan ends in disaster at Zama, it would be the second disaster of a roman army in Africa after Attilius Regulus' disaster during Punic War I.
But as mentioned by others, the consequences for Carthage will not be very different. Carthage still loses all its possessions outside Africa. But it might try to deal with Massinissa without Rome being able to intervene.
The other point is that Rome may have more difficulties in Spain than it had in our timeline. Because at that time, the spanish chieftains considered Scipio more or less as their king. Remember many of them wanted to defect when they believed Scipio had died from disease in 206.
At home, it will be the fall of the house of the Cornelii Scipiones. This changes many many things. There Will be no Gracchi as we knew because Tiberius Gracchus the father will not marry one of the daughters of Africanus.
We may have one generation earlier what happened in the late 170's : the plebeian nobility becoming dominant on the roman political stage and, for the first time, ou string patricians from the yearly college of consuls.
The fact was long ignored, and has been proven by the great historian Munzer, but just after The disaster of Cannae, the Comitiae were going to elect for the first time in roman history 2 plebeian consuls, until Fabius Maximus engineered some kind of coup to replay the election and have himself elected consul.
Rome will also probably take more time before expanding eastwards.