It is correct. If your tongue weight is less than 500lbs just try it with a standard hitch and sway bar. If you need the WD hitch then you should get a frame mounted hitch. The stock hitch is only mounted to the cross member which is not designed to handle the force of WD hitches. It is structural and not easily repairable if bent.
I had to add an aftermarket frame hitch to my old 4Runner. When the latest generation 4Runners came out there was no aftermarket hitch available. It's been a couple of years now so there should be something available now. I had good luck with the Curt brand.
