It's like Expedit -> Kallax, Ikea's always tweaking/value engineering their products and at some point the dimensions become different enough to warrant rename.

It's like Expedit -> Kallax, Ikea's always tweaking/value engineering their products and at some point the dimensions become different enough to warrant rename. I think Kallax shaved 1 cm off the thicker Expedit perimeter pieces to the point where two next to each other perceptually different.