eiii: What's your workaround? Do you request the games sorted by "release_desc", then by "release_asc" (for which only the first page is needed by now) and combine the results? What are the "minor side-effects"? Besides the additional page request I do not see any so far.
The release_asc/_desc sorts were not available back then, when the Y1K bug was in effect, so what I did then (and what I'm now doing again) is instead of getting the entire catalogue as one entity, I get it in five separate queries based on the release filter (pre-2000, 2000-2004, 2005-2009, 2010-2014, after 2014 (note: GOG calls it "after 2015", but it's actually "after 2014")) and combine them into one list.
The side effects are:
1) As you mention, additional page requests (not much of an issue)
2) While this bug is in effect, MaGog has no way of determining the "bestselling rank" of the games on page 41+ (also not that big a deal)
mrkgnao: Someone might want to tell GOG...
eiii: Done. Assuming they read that thread...