There was a recent interview with Hiroyuki Yamaga and Yukari Fukui about GL's finale and the future of the show in a weekly manga-zine released yesterday. They mostly said not so important stuff about what they believed but there were a few fragments of interesting information revealed here and there.
>Nakajima wrote a major number of side-stories about the characters and gave them to the production staff and the VAs, this would help for a better background of the GL world.
>Yamaga doesn't really wants to make a sequel to GL... he would prefer to expand into animation the character side stories wrote by Nakajima.
>Simon isn't virgin... however they had a different idea of how would he lose his virginity during concept stages. He was supposed to lose his virginity to a beastwoman in episode 6, he would get traumatized after discovering she wasn't a human. In the final canon version he just had a somewhat cute but akward first time with Nia.
>The spin-offs they want to do the most would be either about Nia, as Fukui really loved the character and would like to act in a number of her side stories, or about Viral being a guerrilla freedom warrior during the 7 year timeskip.