In this excerpt from Anita Desai's short story "Games at Twilight," which three sentences suggest that the children had completely forgotten about Ravi?

I found the excerpt you are referring to. In her story "Games at Twilight", these 3 sentences - All this time no one had remembered Ravi. Having disappeared from the scene, he had disappeared from their minds. Clean. - suggest that the children had completely forgotten about Ravi. The sentences obviously stated that the children didn't remember about Ravi.