Due to poor sales of Season 2 Volume 1, Disney has no immediate plans for a Volume 2. According to Gargoyles' creator Greg Weisman, the best thing a fan can do is if they haven't bought either season by now, buy them both and also buy the Gargoyles comic books. Slave Labor Graphics prints what is
officially Season 3 of the series. The Goliath Chronicles are not canon and should be disregarded. Gargoyles only recently started printing and is now on book #6. There is also a spin-off called Bad Guys, focusing on a redemption squad of past villains of the series.
If Bad Guys does well, then Disney will green light other spin offs such as Timedancer (Focus on Brooklyn), Pendragon (focus on King Arthur and Griff), and Dark Ages (focus on Castle Wyvern when Hudson was still clan leader and Demona and Goliath were teenagers). It is vitally important to support the series by buying the DVDs and comics, if you want to see the final episodes on DVD and a continuation of the series in comic book form.
You can purchase the comics here:
http://www.slgcomic.com/category-exec/c ... ney_Comics