PCIe card Dimension Half-Length 106.68 × 175.26 Specification Devaiation
The PCIe electromechanical spec says for the half length form factor if the consumption of the power more than the rated power 10W, then the length must have greater than the Half length form factor. Nowadays most of the GPU, CPU, FPGA card built in Half, full length PCIe form factor and these are all power hungry devices hence most of the time power will be exceeding the rated power 10W, this might be the reason for mentioning in Wikipedia also.
Please find the attached snap shot of the PCI electromechanical specification.
Hope it helps.