No, I'm pretty sure they mean international first class, especially since they also mention 'it's surprisingly quiet in the top front', which is where first class is.
Right, they meant that the trappings of first class are so over the top that it makes them uncomfortable.
Odd thing is I thought the 747 was usually configured with biz class upstairs (I got a biz upgrade on a SIN->DPS flight many years ago and flew upstairs) and first class in the front of the main level, so maybe they weren't talking about first class. Or perhaps some airlines have/had 747s with first upstairs.