https://minimaxir.com/2023/11/open-source-dead-github/
The best-case scenario is that you annoy the maintainers.
There is a discussion on Hacker News, but feel free to comment here as well.
Honestly, I appreciate those "is this dead" issues. It's a good way to check the pulse of project before you try to integrate it as a dependency for your own. But really it should only be done of there has been no activity for some time (like 2 years or so). A simple "it's not dead, it's just feature complete" or "big fixes only" would go a long way to assure the community.
I never make those issues myself, but I appreciate the others who do.