A contour cutting machine does need a lift gantry for cutting wire. A lift gantry is used to raise and lower the cutting head of a machine, which is necessary for cutting materials that are thicker than the height of the cutting head. Wire is typically very thin, so a lift gantry is not necessary.
However, there are some contour cutting machines that do have a lift gantry. This is typically the case for fast wire machine that is designed to cut a variety of materials, including wire. The lift gantry gives the machine the versatility to cut materials of different thicknesses.
If you are planning to cut wire with a contour cutting machine, you do not need to worry about getting a machine with a lift gantry. However, if you want the versatility to cut other materials, such as sheet metal, then a machine with a lift gantry is a good option.