Hello, update 1.0.2 released on Steam December 10th and I would like to know when this patch is coming to GOG version. Thx

I realise that this isn't the case and that there is no malice involved, but I could swear the wording of "is live on PC" (instead of the more accurate "on Steam") was done on purpose just to wind me up.

They must! I'm tired of companies treating us as second class citizen.

It's still a bit of an unknown, I'm afraid, and the answer is the same as it was regarding the release of patch 1.0.1 - that it shall arrive once it arrives. In other words, the developers do not know when the patch will come to GOG. Once the patch has been submitted, it is out of their hands. They can only wait for those platforms to validate it, so a precise date other than "soon" (i.e. it has been submitted; should arrive soon, so please be patient) is not possible.
Furthermore, the decision has been made that "all the other platforms will be updated at the same time," and because of the validation processes that are required for non-Steam platforms, this process can take a bit longer than is typical (These posts are from November of last year, but are still in effect today). This means that we are stuck waiting for whichever platform's validation process takes the longest, assuming that it is not our own.

Whether this means we are "2nd class citizens" is interpretive. Is it the developers fault that Steam and GOG have different validation processes; should Dotemu also hold the Steam version back just because of us? Perhaps not. Either way, it could be seen that it is GOG that forces us to be treated differently, rather than the developers being at fault themselves. You might also say that we are being treated "fairly" - each platform that has a validation process has its releases aligned to make them all equal. You might say that receiving a slower, stable release is better on the whole than being the Steam guinea pigs, even though in this case it results in us just lagging behind without important bug-fixes.

Personally, I don't really care when the updates arrive. Knowing that the bugs are being ironed out and the game not abandoned is satisfactory enough. In other words, we are still being actively considered by a development team currently at work. It's not like I have all my eggs in the Metal Slug Tactics basket. The only difference it makes to me is that I cannot in good faith recommend this game until we receive patch 1.0.3, or perhaps 1.0.4.