The airways from KL towards Beijing don't cross over Laos or Vietnam, they are mainly coastal routes that pass initially to the south of Vietnam, in the area of Con Son Island, and on up the coast towards the area of Guangzhou to connect to the airway up to Beijing. So, if they lost contact about 2hrs into the flight they would have been over water, albeit there does seem to be some confusion as to just when LOC occurred. If they went into the water, this would of course hamper any SAR response and could account for the lack of an ELT signal. Weather seems relatively benign, as it is this time of year, and of course, if it had landed anywhere, which it would have done by now, we would have heard. Also assuming no last minute contact with any ATC unit, I think it is sadly safe to assume that an immediate and non survivable incident has happened.
