For all popular free software project, it is necessary to manage the supported versions.
The community (or the editor) in charge of the project release a new version for fix bugs and security vulnerabilities only for the supported versions.
For PHP, all supported version by the community is available here.
What is the link with Win32Service? The link is easy, to build the extension for each change the project uses the AppVeyor service. This service allows building, run automated tests, and keep the DLL for download. The DLL is used by you to test your projects with the new version and send feedback from the result of your tests.
But, to build this extension, I need to use some tools necessary for the PHP build on Windows. There tools are managed by the PHP community. In fact, I can build this extension only for the supported PHP version with build tools.
If you want the new version of this extension for an unsupported PHP 7 version, you must build yourself this extension.