What the Kyoto-based company may have not planned for is a USB adapter that lets you use a PS4 controller with the Nintendo Switch. Accessories manufacturer 8bitdo has released the 8Bitdo Wireless USB Adapter which lets you just that.
In addition to the DualShock 4, the 8Bitdo Wireless USB Adapter supports the DualShock 3, Wii remote, Wii U Pro Controller, and the Nintendo Switch Pro Controller.
Furthermore, you can use the 8Bitdo Wireless USB Adapter with Windows, Mac, Android TV, Raspberry Pi, and Retrofreak devices, meaning you have multiple ways to use your existing controllers across multiple platforms even if you don’t own a Nintendo Switch and have no plans to get one.
Though we’d suspect that the 8Bitdo Wireless USB Adapter would see the most use from someone who has accessories for the Wii and Wii U that can now be used on the Nintendo Switch.