Cathay 777X Just wandering what the 21 777X's that CX have ordered would be used for?

Cathay 777X

Just wandering what the 21 777X's that CX have ordered would be used for? Are they predominantly for the replacement of older 777-300ER's (when its 2020) or are they a new route opener and where would those new routes be?

I'd see them as replacements for the 300ERs to premium heavy long haul routes like London/Paris/Frankfurt. The A350-9s will be more likely put onto routes a little too small for the 777, like Madrid and Dusseldorf (Brisbane and Perth might play in too). The 350-10s I could definitely see on the Sydney and Melbourne routes.