I have noticed this too, however my experience has been:
- Select flights purchased with a credit card (spent money), onshore. This includes calling about upgrades since the initial fare would have been purchased with money.
- Select flights booked with points (didn't spend money) and velocity member enquiries, offshore.
I don't like it, but it does make sense from a business perspective. Have your more expensive staff handle the transactions that make your business revenue. Offshore the cheaper transactions such as account enquiries and reward bookings.
While I agree I have noticed a difference in service, more just the general conversation and the quick knowledge of the onshore team. I haven't had any major drama's with the offshore team and everything is managed well.
I did however recently have a complaint dealt with by the Guest Relations Team and which I am pretty sure it went offshore, based on the agent name, scripted response and english standard. It was awful. For an escalated complaint it was handled dreadfully.