Yes, But we're not talking "Stress" here... We're talking about "Shear"

You are better off having gaps in between the ribs and the shear webs, but having the webs go the ENTIRE length of the wing, then you are by filling the gaps and stopping the webs half way out.

Filling the gaps (with the webs going the full length of the wing) is like screwing your brick BBQ grill to the ground so it won't fall over.

Does it help? Yes.

Is it needed? No.