Often, "they are coming g" is used by creators or brands to build anticipation for a new release, collaboration, or major announcement.
In urban slang, especially within gaming or tight-knit crews, “They coming, g” alerts a partner to approaching rivals, police, or opposing players. The “g” stands for “gang” or “geezer” (friend). This usage strips the horror and replaces it with tactical urgency. they are coming g