I moved away from my hometown nearly 8 years ago. I was really close to a lot of people before that (I've known some of them since preschool), but I moved, and grew further apart from them naturally as time went on. This is mainly because they all hung out together in person, and while I attempted to stay in touch with them over the years, I never really found success in doing so.
I did like to lurk on their discord server occasionally, mostly so I could see what some of them were getting up to. I would occasionally react to their messages in their discord server, but that was pretty much it for the last 3 or 4 years. It made me feel a bit of nostalgia and made me happy to see the people they were growing up to be. I don't have social media other than here and discord (and I've frankly been on discord less and less), so it does kind of feel like a bummer that I won't be able to see their messages anymore.
I don't really feel any anger over it since we had grown apart, but I do feel some type of sadness that I can't quite identify. It's probably because in the 8 years that my now wife and I have lived where we do now, we have struggled to meet new friends. I legitimately have no in person friends other than my wife, which is not a healthy place to be. So, I suppose this feels like officially losing almost all of my in person friends, past or present.
There's still a couple that I occasionally chat with on Signal, and ironically I'm in my hometown visiting family right now and will see one of them in a few days. I might ask them about it, but again, I'm not expected to be re-added and I honestly probably shouldn't be. Maybe it'll push me to want to put the effort in to meet some new friends.
For now, though, I'm just oddly sad. It definitely doesn't help that I'm here visiting when I was removed, I guess.
Edit (update): friend I visited today said that they sometimes clean house and added me back.
Not everyone is meant to be in your life forever, I don't really know any of my old friends from grade school anymore except two and I married one of them.
Still sucks though.
I agree, I've not talked to many of the friends I used to have in grade school in over a decade. It's natural. This time just felt different, I guess. Someone had to take action to remove me. Again, I can understand why, and it's probably just time to close the chapter anyway.
Given your probable age and the way you described the group, it's possible that some group moderation duties got handed to a spouse or someone else who doesn't personally know you in the same way that the original group does, and that some parameter for inclusion got changed either by Discord or by some inadvertently tightened group setting, like frequency of use. I don't know Discord so I can't say, but that would be my guess.
Which is to say that while you may be right, I wouldn't take it personally just yet. There's an email list that's been going on in our house (email, I know, lol) involving people that went to school together in the 70s, which is to say you never have to close the chapter if you don't want to. Shit happens with us too, but honestly it has only ever happened by accident.
Wait and see what your friends have to say about it. I genuinely hope you ask, just to give yourself the peace of knowing for sure, and also to give them the chance to right the wrong (if it was accidental).