I’ve experienced this same thing with a number of different shows I’ve been a fan of - once the show gets to about season 4, and its ratings are fine but not amazing, the network just stops promoting the show. They want to invest the money in promoting newer shows which could potentially be a bigger hit for them. I’ve read that after about the second of third season, most shows steadily lose live viewers each season. The best most shows can hope for after a certain age is for their ratings to hold steady, because generally they’re not going to increase. it’s a consistent pattern and the networks know this. I think they don’t believe it worthwhile to invest in promotion for older shows because to them, there is no real point. And, no the networks don’t care about fans at all. Any promotion of the show is usually aimed at new viewers and casual viewers - they’re the ones they want to get, because they know the diehard fans are going to watch anyway, no matter whether they promote the show or not. It’s disappointing but it’s the way it seems to be.