I guess that means alitalia is staying 
If Alitalia is here, why not have other bust airlines such as Thomas Cook or Monarch
Those might come later on as they aren’t currently in the game and are retired liveries
Right now their focus is on replacing current liveries already in the game
Thomas Cook is in game though
Not for narrowbbodies
Thomas Cook is present in the game, but will not particularly be seen in the playable European airports.
As currently the only aircraft with the Thomas Cook livery being the A332 (A330-200), you will only be able to use the livery on longer destinations from UK airports. You can usually find it stationed at Manchester.
For example:
- MAN - IAD (Manchester - Washington Dulles), there will be a Thomas Cook present.
- MAN - PRG (Manchester - Prague), not a long haul route from the UK. No point for the A332 to be used on such a short route.
There is a good chance that they might develop more for Thomas Cook later down the line, as they are focusing on improving already pre-existing liveries for the A320 family, which is why the airline isn’t going to be present here.
Looking at it logically, there is a good chance that Thomas Cook’s A320 family liveries will come with the 757 design update, as Thomas Cook operated that plane for themselves along with some under Condor.