As far as I know, there are no official Raspberry Pi add-ons or modules specifically designed to enable 5G connectivity for the CM4. The Raspberry Pi Foundation primarily focuses on providing affordable single-board computers and related accessories, and they have not announced any plans for developing 5G modules or add-ons for the CM4.
However, it’s worth noting that the Raspberry Pi CM4 features a PCI Express (PCIe) interface, which can potentially be utilized for adding third-party cellular modems or expansion cards that support 5G connectivity. By using external 5G modem solutions, it might be possible to integrate 5G capabilities with the CM4. You would need to research compatible 5G modems, availability of drivers, and any necessary software support to enable 5G connectivity.