I kind of agree with you that having this distinction would be useful. The real key is it isn't about "dev work". It is a cross between Ops, Dev, and Build. The build is actually more important than the Dev. Even bigger is who you report to. In the old world as Ops you reported to an Ops manager. The to Devops is that you report to the Dev manager, hence breaking down the silos. You could just call it Devops, but I call it embedded Devops to be clearer.

On the flip side I seen just how poorly Dev managers and Dev team leads can understand Ops. It is even worse when they think they do, but don't. This can make Devops painful.

There is also a problem with having an individual Devops on each Dev team. You will end up with each Dev team doing things completely different ways. One will be Ubuntu, one Debian, one CentOS, one instances, and one containers. There should be some standardizing force across the teams.