It is not a new invention. It is mentioned in the Fourth Geneva Convention from 1949.

It shouldn’t be that way. Acts like rape and torture should unquestionably be considered war crimes. So should the use of armed forces without identification marks (such as uniforms), the denial of access to prisoners by Red Cross personnel, and attacks on civilians when there is no intelligence indicating the presence of combatants among them. However, banning forced relocation altogether can have unintended consequences. It encourages the deliberate placement of civilians in disputed territories to establish permanent claims. That’s counterproductive. The losing side in a conflict should take responsibility for its civilian population in the territory it lost.