Why did this flight disappear from inventory?
 

I know there have been posts on here recently about flights missing from people's upcoming "my trips." This is NOT quite that.

so yesterday I bought YYZ-FCO on(3/10/16) and then FCO-ATL-YYZ on (3/15/16) I made my purchase, ticket was issued, got seats. all good. Later in the day, a friend decided she wants to join me and wants to mirror the same itinerary. The FCO-ATL flight now doesn't exist. When I booked yesterday there were PLENTY of seats for sale so I can't imagine it's sold out in a matter of hours. So I called DL and the rep said she can't even pull up that FCO-ATL flight on her end but confirmed that I'm booked in it for 3/15. The flight exists for 3/13, 3/14 and 3/16, etc. so why would that flight now all of a sudden not be showing up just for that day (3/15)? truly puzzled and would appreciate any insight.. Thanks.

The flight shows up in availability, but shows completely sold out. My guess is that Delta is running a schedule change tomorrow and that flight will either disappear or the equipment will change, so they have inhibited sales on the flight. I would check back on Sunday and see what has transpired.

I was going to suggest checking availability on EF but unfortunately we can't do that any more.

In this case we actually can because it's an AF and AZ codeshare. Of course the DL coded inventory could be completely different, but the AF and AZ codes both show 0s across the board.

I think Mr. Tickets is right, and you should expect a schedule change or outright flight cancellation coming up soon.