I have heard that Mainland China has set up a 10 year plan to return to traditional characters.
Is this true?
Where did you hear it? That might help you to judge its accuracy.
There’s this thread: PRC use traditional Characters = Reunification with Taiwan, which offers some links.
But most of the debate throughout the Net and in China is shallow and fails to address fundamentals. As for the PRC dropping simplified characters, it’s not gonna happen. But maybe the traditional ones will be increasingly allowed.
If anything the younger generation will be able to sing Taiwan made KTV as they are all using traditional characters.
The Economist article attributes these policies to the person of Mao Zedong. Can anyone find among Mao’s voluminous writings anything to indicate that this issue was a major concern for him? Actually Mao Zedong wrote in traditional characters, but often used grass script (caoshu), from which some simplified characters, such as the “dong” in his name, are derived.
I don’t think it was a major concern, but he was personally involved. From Baidu: 1953年毛泽东主席指出：“作简体字要多利用草体，找出简化规律，作出基本形体，有规律地进行简化。汉字的数量也必须大大减缩。只有从形体上和数量上同时精简，才算得上简化。”
Mao was certainly involved, though he flipflopped some. See, for example, The Chinese Language: Fact and Fantasy, pp. 257 ff. Whether this was a major thing for him can be debated. But his influence on the direction taken was major, simply because he was the boss.