welcome to the 
forum, @d33tah
this is getting formalized as we speak. In the meantime, I believe that our general policy is to provide support for one major version (7) below the current version (8). So Grafana 6 is effectively EOL now. Does that help? G7 should still get critical updates
now having said that, G8 is a quantum leap forward from G7, and you can’t use the new, rebuilt alerting platform unless you are running 8. So, given the new features and breaking changes, I generally recommend that folks get on this side of 8, sooner rather than later if they can 