It is in part related to the restrictions in capacity in the South East. New or extended routes cannot get into LHR or LGW look at MAN and BHX.
Clearly some demand exists for LHR outside of the south east it is, in part, simply reallocating services in a more geographically appropriate way.
Agree with SQ. If CX go daily and the likes of Emirates and Etihad keep increasing frequency, not to mention all of the Chinese carriers, they need to change something. Offering a daily service non stop on a brand new aircraft seems like a very strong response.