I don't think so, in Napoli's latest match, Lukaku was not in the squad, instead of playing Højlund, Conte preferred Lorenzo Lucca as a starter. Napoli's next match is against Fiorentina & it's not impossible that he'll feature in that crucial clash. It would also be an opportunity for him to prove to Conte that he belongs at Napoli. But back to my initial thoughts, I'm not sure Højlund will play. It might take some time for Conte to get him back into the side.
That's because he simply signed recently for them and is yet to even train properly with the first team for a general assessment. What's the reason of his signature if he won't be the center forward for them?! They must have had that discussion before he concluded to swi g that way. After the International break, I'm certain he'll be the man leading the attack. He had a good past with Atalanta, I'm sure he'll smash it with Napoli.
Lukaku will be the top striker any day at Napoli Hujlund is just a backup in case of injury to lukaku before conte brought him to napoli he has plans for him , lukaku has not settled down properly and just as you have said after the international break I believe that lukaku will start his journey in Napoli.