Got back from a run to Kuala Lumpur on Malaysia Airlines.

From HKG to KUL: all announcements were done in Malay and English by the same person followed by a Chinese-speaking flight attendant in Mandarin right afterwards with no delay. Most announcements begin first in Malay, though a select few begin in English first. This includes all pre-take off welcoming spiel (even announcement from the cockpit) which CX does in English only on all flights. On CX, the first announcement in Chinese or any other language would only come after take off.

From KUL-HKG: Almost all announcements were done in Malay/English/Mandarin, though I remember a few announcements were not repeated in Mandarin.