Would greater success in 1973 have saved Anwar Sadat?

If the Egyptian Army had been more successful in 1973, would Sadat still have been assassinated after making peace with Israel?

Probably yes, because the objection was to making peace itself rather than to how well Egypt had fought in 1973.

The counterfactual leaves Sadat's peace with Israel in place while giving Egypt greater battlefield success in 1973. Under that condition, the proposed explanation for his assassination still applies: the grievance was making peace. For opponents who treated compromise as worse than losing a war, a stronger campaign would not remove that objection. The prediction therefore depends on the political act remaining unchanged.