Toyota Prado tow bar

Toyota recently recalled my Prado 120 concerning the tow bar, and they replaced four bolts and fitted a new gooseneck. They also talked me into replacing my shepherd hooks with a Toyota WDH brand. It would appear that the Prado cannot handle the aftermarket weight distributor hitches and they want us to use the Toyota brand. This was all done at no cost to me, which makes me more suspicious as we have never had a problem with our shepherd hooks and they did not ask us what size of caravan we were towing. Are the Toyota hitches strong enough?