Can an LED wall be curved?

Yes. Curved walls are built by angling standard cabinets or by using a shaped cabinet, and the radius is agreed before the cabinets are ordered.

Angled cabinets

Flat cabinets set at an angle produce a faceted curve. The facet count is chosen so the steps are not read from the viewing distance.

For columns, ribbons and irregular outlines the cabinet itself is shaped to the drawing. That is a design decision, taken with the elevation in hand.

A plan view with the radius and the viewing positions is enough to start. The cabinet layout comes back as a drawing with the facet angles marked.