The problem is not the "expectation" of ownership. The problem is in lack of clarity in communication. For whatever reason (usually because they're very good), a lot of Andrew's libraries became very popular in the Go world. If his interests have changed to Rust, all he needs to have done is say so.
I'm not faulting you for your expectations, please see my other comment for thought on that. The problem is that even expecting that is more free labor. Sure it's small, and courteous, but is labor. Speaking from experience, I go through weird phases where I want to hide from the world. I know things suffer for it, but it's me. And even writing a short note to let people know is not on my radar as something I care about.
I hope you don't take my comments as combative, I'm trying to speak from experience. I also learned of Mr. Gallant from being on the Go code review lists. I also noticed he seemed to "switch" to Rust. With that knowledge, anything I used heavily I would fork. If one day the two can reconcile, great. If not, congratulations, you own it until you get tired of it and someone else forks it. Such is the nature of open source!
Deciding that you don't intend to maintain a project is labor. This sort of decision is hard to make and extremely hard to undo. Much easier to keep thinking, "I'll get to it next month."
