My opinion on that question woudl be this:
If you plan to develop your own concept work, to be done in 3d, then a working knowledge of aspects of 2d work would of course be very useful.
Otherwise, While yes, knowing how to put pen to paper Would be a useful skill in art as a whole and could not serve to hinder your efforts in 3d, i do not see that it would its self enhance your ability as a 3d artist.
However Art is not something that is learned. A person either Is an artist, or isn't. Yes you have to learn the software you are using and techniques that need to be employed for this and that. But a person who is not artistic or imaginative can know all day long how to Use the software in question and not produce a scrap of art with the knowledge.
Anyone with time and dedication can reproduce any object they see in a tutorial as they watch the tutorial, but Not everyone can take those skills and apply them to a different object to recreate it.
Also, I have found at least for my own work, i woudl not know for sure about industry work, but having a bit of imagination when dealing with concepts is necessary. you have a road...ok so you can model the road, but the concept doesn't show other bits that might make it look nicer, Light poles, Street lamps, fire hydrants, ect, an artist would be needed to employ that sort of addition to the concept.
Jay, whats say since your an uber mod, you copy some of these last few posts to a different thread for this type of advice, maybe make it sticky, so that your alien character isn't hijacked any further?