From what I've read ITA will need to be completely separate from AZ. This includes not accepting current AZ tickets. However I believe EU law requires EU carriers to offer some type of accommodation to customers with tickets on defunct airlines. However I see AZ is still selling tickets for flights next year. At this point they know they stop flying on Oct 14th, so it would be weird for ITA not to accept AZ tickets.

Bottom line, I don't think anyone knows 100% for sure. I would make sure any AZ flight is ticketed on another carrier stock till then.