I don't think php has reached the point where a lot of libraries have reached stagnation.
In general though it would be cool to just automate this in some fashion. Occasionally email participants a link to projects that haven't had commits in many months but have open bugs or feature requests.
It's not necessarily _just_ about dealing with stagnation. It's also about finding a way for people to start contributing to open source. If you've never released anything, just patching someone else's work is a great way to start. This automates the selection process so you don't necessarily have to look around for something that needs help.
Compared to CPAN, PHP is fairly monolithic. Many of the OSS projects that we hear about are sponsored and/or open/closed or the Automattic business model.
Many CPAN modules are blobs of arcanery and some work completely well but are relatively abandoned.
In general though it would be cool to just automate this in some fashion. Occasionally email participants a link to projects that haven't had commits in many months but have open bugs or feature requests.