Another choice would lead to the uchihas dying anyway. The coup would happen and not only they would have more loses in both sides but sasuke would die as well. It’s also mentioned that if the coup happened, other villages would take advantage of konoha’s current state and they would probably start a war.

Itachi made a choice that essentially not only saved konoha from an all out war, but also retained the uchiha clan’s honor ( since now they didn’t die as traitors to the eyes of the world). Obviously like you said, most importantly for itachi, was ensuring sasuke’s life, so again that choice ensured that.

Itachi was forced to make a very hard choice, but there is no denying that the choice he made lead to less bloodshed. The only counter arguments I see people having, are vague ideas that a 13 year old itachi would suddenly make the uchihas magically call off the coup. To me, that’s childish. Sometimes there is no easy way out.