I had two 1 night stays here about a month ago, the first stay I arrived pretty late, and was given an executive king. The second, I arrived early afternoon and was offered a really nice suite. So it would seem (like with many South East Asian properties I've found) that they are pretty good about upgrading where they can.

Although that said, as far as I can tell from the photos, the executive room is actually just exactly the same as the deluxe, and even classic, apart from being on a higher floor and with the lounge access that you would already get as a HH Diamond.