There are two possibilities with Luca's survival, hinging on one question; does he reflect and feel he was put in an unnecessarily dangerous situation when he met with the Turk?

If so, he will find himself in quite the quandry. He can no longer trust Vito (and, by extension, his family) but Vito's enemies tried to kill him. He would have nowhere to turn and would either flee the country altogether or go out in a brash attempt at revenge.

If not (which I think would be the case, as I doubt his mind would allow him to contemplate the Vito would do such a thing), then he remains loyal to Vito, and by extension, his sons. If the meeting didn't cost Vito Luca's loyalty, nothing would. While Michael would probably phase him out upon taking over, he would still provide him with a role and treat him with great respect.