In one line my answer would be, - No, there is no need.

It is not necessary that one has to draw well in order to make a career in 3D Animation and Visual Effects

But if you go a little deep into it, then you will understand that 3D Animation and Visual Effects (which you may call CGI industry) is divided into several departments. And all of those different departments demands different skill sets from various artists. Now you see,- few departments like the rigging, lighting, rendering, stereoscopy etc will require zero to very minimum level of drawing skills from an artist. Whereas, on the other hand, departments like the character animation, storyboarding, character designing, mat painting, texturing etc will require moderate to very high level of drawing skills from an artist.

So, a correct answer to your question would be, whether you need to have drawing skill or not is totally based on the type of work you are planning to do. But there is no need to panic if you cant draw, as there are many positions in the CGI pipeline where you can fit yourself perfectly even without that skill.

Hope my answer helps you. Best of luck