If you grep for 'route_name' in 8.x right now, you see a lot of ones that look like this:
./core/modules/language/language.module: 'route_name' => 'language_negotiation_url',and a few ones that look like this:
./core/modules/views_ui/views_ui.module: 'route_name' => 'views_ui.list',The easiest thing to do is convert the views ones to under_scores, but I actually prefer the dot-convention myself, because it makes it clear that these are not callback functions, which they kind of look like.