I suspect the 'Light' refers to locomotive weight rather than emissions. I don't expect that anyone will pick up any Tier IV export power unless their emissions standards require it as they are costlier to purchase, run and maintain.
Also my impression. The point that I had being trying to make quoting the previous examples of US export locos, is that unless other nations adopt stringent US Tier 4 regulations, then the current generation of US domestic J and GEVO engines, will be restricted to North America. Those arguing that the prior generation of US loco diesel engines are dead and buried, are blinkered and delusional, and not looking at the evidence from export and licensed production (including marine and stationary). Why would Caterpillar close the 710 production line if it is still cranking out well over 1000 engines per annum?
Europe with its minuscule loading gauge, looks to have taken to the high speed diesel with exhaust treatment to meet European standards. With Europe we are dealing with first world countries, where operators can afford to either have the engines maintained by the manufacturer, or are leasing a fully maintained engine on a power by the hour basis. European practice is unlikely to flow into the third world. European freight locos are designed to haul short drags at passenger loco speeds
With China, it is important to differentiate between export and domestic, there is a huge difference in design philosophy. Domestic loco design is the monopoly of design bureaus attached to some of the prestigious engineering universities, hence designed by academic engineers with no commercial acumen and little real world experience. With domestic locos it could be argued that it is in the Parties interest to maintain the use of the shoddy, short life, medium speed indigenous engines currently in production. https://en.wikipedia.org/wiki/Iron_rice_bowl
The Iron Rice Bowl philosophy has meant that the various railway operating units, still maintain steam era backshop manning levels. Communist practice dictates that all of these little vegimites require the work unit to supply housing, family health care, and kids education. Better to keep them busy maintaining the crap domestic locos (with CRRC cranking out replacements), than face social upheaval. Critical services, and the high altitude lines north of the Himalayas, use locos powered by license built GEVO and H engines, of which well over a thousand are in use