Vitara trailer load 2020 1,200 kg from 2021 1,500 kg

Hello together, can someone tell me why the Vitara from 2020 (ordered in 2020 by the dealer and now delivered and sold) has slowed down a trailer load of only 1,200 kg and is shown in the current catalog a trailer load of 1,500 kg? My dealer has only told me that there is a circular for this. Can one easily increase the trailer load ? Does one have information about this ?