It's not a complete change. The caver is that the great majority of trans prisons will be allowed to serve in the gender they identify in a review of guidelines.
But its suggesting its a nuanced approach on a case by case, which I would assume involves a risk assessment.
Technically speaking I believe that's how the law should be working in all areas, but precisely what activists are trying to stop.
Im sure not everyone here will be satisfied by that, but its a significant point in stating you CAN legally do this and we should be doing so.