I notice that the GroupLayer class at 100.5 has a quirk similar that of an earlier (pre-10.2.7) release: when a sublayer has labels enabled and the group layer is initially not visible, the labels still appear. However, when the layer is made visible and then not visible again, the labels go away. Is there a better practice for creating and adding group layers?
To try to explain the situation better: in the past, I've routinely loaded layers to get their info before adding them to the map. At 100.5, this can break layer behavior, especially if a reference scale is defined. I've come up with a workaround, but it's a bit clumsy, and I'm still trying to work out a more elegant way to get what I want..