After reading the quotes yesterday, my initial thought was that Lukaku's intention behind this interview was to repair the relationship with the Inter fans, who were clearly aggrieved at the circumstances of how he left the club.
However, these quotes which have been publicised today are absolutely insane. Just 6 months after joining Chelsea for a club-record fee and supposedly being a 'Chelsea fan'. These quotes today certainly don't come across as someone who wants to be there.
He isn't just talking about going back to Inter 'one day', he said he wants to go back in 'his prime' and that he effectively wants their best players to remain there because he'll be back soon

. Not what you want to hear from a player you've forked all that money on.
Also, Lukaku isn't stupid. He can speak 6 languages fluently. He's not unaware as to how this would come across, even if the interview was 3 weeks ago. Ornstein was saying that even his representatives had no idea he'd done this interview. So I'm beginning to think the intention is more sinister and perhaps he's trying to push Tuchel out? I can't think of any other tangible reason of doing an interview like this. And the timing of it being released as well - surely he'd have a say in that, too.
Mental.