Well if there isn't a G+ Community for the game I want to make content for, I could just make it and market the heck out of it to help drive traffic to it. That's always a possibility. If fact I probably will end up doing just that.
Google+ is probably one of the most under utilized social media platforms that YouTubers use (we all have a G+ Profile so everyone has one just not everyone uses it). Plus it looks good to YouTube if you're using their platforms in combination with one another. So I don't know why more YouTubers aren't jumping on board with it since it's really user friendly and very clean looking. It isn't cluttered like Facebook is.