The forum isn't going anywhere and there are no plans to merge it. George and I, and other forum members, have just been busy with life, other site stuff, and the Discord which has been VERY active. Discord doesn't replace the forums, but it sure has shown itself to be another great way for the community to chat and keep in touch. I check the forums nearly every day, I just don't post here daily.
Also worth noting that when the site started, it was the comments and forums. Now, it's Twitter, Facebook, YouTube, Instagram and Discord. As far as all of those, SEGAbits is pretty much top dog in terms of followers and discussion in every one but Facebook (a certain other site bought likes). The social playing field has expanded and as such, there are more people but they are spread out. Forums are becoming an older, less popular method of interaction but they are not going anywhere.
The idea of merging with a general gaming site was something Nerds tried with The Kartel and that was a disaster. Different communities suddenly had all these new people who didn't like their focus or didn't share how their community interacted. It was a mess.