I think the original pitch was the SG program gets disclosed on Earth, so you have to deal with political and societal ramifications of that and you'd have a new SG team doing stuff. It wouldn't delete the prior stuff, but would sort of provide a new angle because you'd have people unfamiliar with the SG program and it would let you introduce the audience to stuff, while longtime fans would recognize it and see continuation. I can see why that might not be super compelling to a wider audience, although the classic problem you run into is the longer you go on, the harder it is to make both audiences happy.
Like I'd absolute love for them to continue Farscape, but I also understand the show ended over 20 years ago, so doing a direct continuation straight up would be a very hard sell and you'd need something that could satisfy old fans and new fans, which would be quite hard to do.