Content access can currently be set in the workflow. It is very flexible in status, but it is a lot of work to set for all statusses.
To feature this a "Read content" and "Write content" will be added:
Multiple users groups can be added to a channel
When no groups have been added, everyone has access
Add a "Read content" and "Write content" setting to the /admin/contenttype/new and edit page. The placeholder is "Everyone". The component is a multi select2 for group selection, same as for the workflow
On the workflow edit page, add a "Inherit from content type" placeholder for Read and Write (this will be the case when not specific rights have been set for a status)