I'm in my early thirties and adamantly childfree. I'm lucky enough to be in a long-term relationship with someone who brought up her desire to be childfree on more or less our first date. But I am not having too much luck with my friends from childhood and university - they all seem to be wanting kids, and learning of their pregnancies leaves me with a feeling of sadness. I don't hate kids and think no one should have them, and I am happy for them if they truly wanted this, but I also know what them having kids will mean - we are essentially putting our friendship on hiatus, and I still don't know whether waiting 10 years for the kids to be a bit more independent and not requiring as much attention will mean I suddenly have friends again, but somehow I very much doubt it. And I also don't want 10 years without other friends than my girlfriend. She is in very much the same situation, and while we are good at making the best out of not having kids and stressing about having them, we both would want to be able to hang out with good friends once in a while, both common between us, but also some that are exclusive to each of us.
My assumption is that this is quite common - so I am hoping someone would like to share some success stories in turning this situation around. :)
That uncle role is not something I am looking for, though. I am after adult relationships, and it is the loss of these I am saddened about. For the record, I do not blame neither the parents or especially their kids for this change. They do not owe me a continued adult relationship for our entire lives. It is completely up to them to pursue this life, and as I said, I am happy for them as long as this is what they really wanted, and I agree that their kids should be their priorities once they have had them. But so far, in my experience, the kind of relationship becomes completely different. For instance, my girlfriend and I were invited over for dinner to one of my close friends from my twenties, his wife and their two kids. After we left, we were both left with a feeling that we hadn't talked with them at all - we were interrupted constantly by their kids seeking their parents attention. Some parents handle this better - I know others who are better at setting boundaries for their kids and teaching them to not interrupt and wait for their turn, but the interactions with them are still very different - their lives almost entirely revolves around their kids. I was once involuntarily part of a conversation regarding the color and viscosity of kid's shit.
When I reread my original post, I realize it could be interpreted like I want to somehow get things back to how they were before. I know they won't be, and it's not what I meant. I was simply after real stories (i.e. not imagined solutions) of how people in a similar situation, having experienced a similar loss of close friendships, ended up with either new, great friends with a similar outlook on life or anything else that improved that part of their life.
I'm sorry to tell you, the real solutions to keeping friends after they have kids are what you've said you don't want. So, for you, it looks like you've already decided you don't want to be friends with people who have kids. That leaves you with a much smaller pool of people and in an age bracket where it's much more difficult to meet people.
Maybe try finding hobbies that don't have kids in them.