From GI.biz: “Electronic Arts has offered an explanation as to why four of its classic titles were delisted, then relisted on popular PC games marketplace GOG in the past few months.

GOG served a notice towards the end of June revealing it would soon remove Ultima Underworld and its sequel, Syndicate Plus and Syndicate Wars from its marketplace. The site said at the time this was “on publisher’s request.””

Source: N4G PC EA will consider "player perspective" when delisting titles after GOG misstep