Well, the game is not like the TV series, so it will make it own endings. Also, about the TV series, looks like the season 8 is not the end yet. I've heard rumors that they are planning to bring a new sequel for GOT TV series... Looks like Kit Harrington is confirmed to be back as John Snow.
Yeah, the rumors you heard are true. A Jon-centered show was announced months ago. In fact, at some point 8 spin-off projects were being developed, two of which have already been cancelled.
I don't know what they are smoking at HBO, but it must be pretty strong to think this franchise can sustain so many projects. It's true that House of the Dragon seems to be quite successful so far—although I must admit I didn't like the first season at all—but I think they are vastly overestimating the public's interest in this universe.
Anyway, even if all of them turn out to be shit, having more shows means more possibilities for FunFiction to offer us some spicy version of them. Even House of the Dragon could be a good basis for a porn game, especially since Targaryens are the focus and, well, we all know their peculiar family traditions.