Two Kinds of Progress
My first reaction was that even if the protesters are successful, it wouldn't count as progress. The protests apparently are directed strictly at cats, so it's easy to move to the common complaint about hypocritical within-animals speciesism by which people happily eat factory-farmed chickens but object to cute kitties being harmed. (I should point out that since I'm just going by the AP article, I don't know the details of the protestors' philosophical positions.) Though I'm no expert in Cantonese food, I would guess that if denied a dish with cat, most diners would opt for another meat dish -- say, chicken -- rather than tofu or another non-meat option. So a successful ban on the cat industry would just shift the suffering onto another animal, making no net progress from a global perspective (there may be progress if the number of animals involved in producing the quantity of meat is drastically different, or if one species is treated much worse in its raising and slaughter, but I don't have nearly the information it would take to calculate this).
But then it occurred to me that improvements in the actual situation are not the only form progress can take. Progress can also be found in moving closer to the realization of some improvement in the actual situation, even if the new situation is not intrinsically better. And I think that stopping the eating of one species can move us closer to not eating any animals, even if the total amount of animal suffering doesn't change until we reach that end point.
The key here is that it's likely that animal industries can be reformed or shut down on a species-by-species basis. That is, if one's society kills one million cats and two million chickens a day, it's far easier to get the cat industry shut down than to cut the chicken industry back to just one million. Thus defeating one species industry moves us a step closer to defeating them all, even if each shutdown does not improve animals' lot because it just concentrates the suffering under a smaller set of umbrellas. Eventually, we'll (hopefully) get rid of that last umbrella.
Doubtless this kind of progress, in which we get closer to the realization of the goal without conditions improving incrementally along the way, is found in other situations too.
*In part, I'm sure, because it strokes our idea of crazy furriners eating inappropriate things -- though it seems that the facts about the Chinese cat cuisine industry are accurate.