The flight is next Tuesday, I noticed and called yesterday and, as an update, the official flight change notice email arrived sometime last night, after I had called and sorted the new schedule with the agent. So there's proof that they notified me 5 days before the scheduled flight. I see on their website that they are having flight changes due to "operational reasons" (seems that they're wet-leasing): https://www.iberia.com/es/latest-update-of-our-flights/