There will be an update to main Metrostroi addon sometime in the future based on community updates.
New scripts and content for servers(or singleplayer) can be found here[github.com]
Community addons for metrostroi are:
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=489006102
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=759320359
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=759301144
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=625762942
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=781303652
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=820041990
New circle map:
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=674649096
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=719653058

The development is now done by the Metrostroi community. You can follow it at:
On twitter
In VK[vk.com]
On facebook[www.facebook.com]
On instagram[www.instagram.com]