Have flown that route a couple times and can't say whether it's elite or front-end heavy. But I think rather not as I couldn't recall the J cabin to be full those times - but that's only anecdotal experience. Looking at immigration lines, there are quite a few OFW flying in Y and holding their pack of documents to enter DXB.

As GO that time I've been upgraded twice, once on DXB-HKG and another time together with my wife (that time GO as well) on HKG-DXB. But I've been as well on a couple of legs without op-up at all. No experience on SL though.

And yes, for sure they are competing with Emirates, which can offer cheap fares not only because of the fuel but as well since they use HKG-DXB and HKG-BKK-DXB as feeder flights to connect to other destinations like LHR, etc. and may have some free seats to fill up. Another possible reason for CX to offer cheap fares is that demand might have slipped with DXB in debts since economic recession, stopping a lot of construction works, companies terminating expat contracts, etc., but that CX still wants to maintain their schedule for pax and probably belly cargo as well.