Your network should be somewhat transactional. They don't call it your friend circle or your family, that's different.
Your network are people who can be (potentially) useful to you in your career or life goals. In return, you typically are (potentially) useful to them.
The oft-repeated story of a colleague moving on and then giving you a recommendation for hire at their new gig when you start looking is a transactional relationship. Both parties got something out of it, and I don't see anything wrong with acknowledging that. Even if those parties didn't really speak for a few years in between.
Plenty of folks I consider in my network and "good" friends I haven't spoken to in a couple years. If they called me at this moment I'd drop everything and pick up the call, and at least try to help them with whatever their reasonable need is. And I expect the same to be similar in reverse as well.
Hahaa, citation needed.
Embrace the interpersonal blackpill... unu
I guess what I'm getting at is that I wouldn't be offended if an old coworker contacted me about a job after not hearing from them for years. We're all busy and have many priorities in our lives. It's kind of understood that we can't keep up with everyone.