"Whats in it for them?"
Lowkoon,
Don't understand the "them" in your question. Be in no doubt, this will be driven by Cathay, ie Swire... and the various departments are under pressure to reduce costs by way of the takeover (Economies of scale). Watch for the following;
1. FLt Ops will want the ability for all 330 qualified pilots to fly any 330. To do this the Ka and Cx SOPs/ checklists are going to morph into one. The 744 procedures are identical as they were formulated by the same chap!!
2. Rostering will be done by the same dept. New roster practices coming Ka's way... that could be good news....maybe...?
3. To stem the flow of pilots leaving Ka, they will have to offer at least the "prospect" of access to Cx bases and lifestyle rosters that come with ULH... is that a light at the end of the tunnel... or a train coming the other way?
For Cathay/Swire, putting Ka pilots on the bottom of the Cx list is a quick easy fix as it avoids a fight with the larger pilot group. However, whether it achieves the important point 3 above is up to the Ka pilot group.
This whole issue doesn't even feature on most Cx pilot's radar yet, so the ball's very much in your Court chaps.....