Chiming in a bit late.
I believe frontend devs should have basic knowledge of not just Node, but what goes on in the backend in general. Same for UI/UX design. Not saying they need to be masters of each domain and be fullstack devs at all, but there's a lot of empathy to be gained from understanding how each part of the product you're building works. In the workplace, it opens up more dialogue with the rest of your team (or other teams, depending on how your company structures its engineering efforts).