I imagine that this isn’t a bug, because it kind of makes sense that if something is disabled it would be disabled in terms of rendering as well. However, it wasn’t always like this. In one of my games, I use a RopeConstraint as the line of a fishing rod. How it used to work is, when not in use, it is connected to the rod, and when you cast it, the rope would be disabled (so it doesn’t take you along with it). This used to leave the rope rendering, and it would create the effect of the line being cast. However now, the line just goes invisible when it’s being cast, which threw some of my players off, thinking it broke.
This is not new, it’s a change from January. Yes we had to make that change for technical reasons, as well as because it makes sense. Of course it is arguable what it means to disable a constraint, but we felt it also means the user doesn’t want it to render. Sorry for the inconvenience.