Frankly, I think that Khrushchev and company were glad Trotsky was dead when they decided to go forward with De-Stalinization. Trotsky being around would have probably made reform a lot more difficult, and a lot more toxic. Trotsky would be on the minds of the conservative Soviet politicians, being the great boogieman. Trotsky alive embodies opposition to Stalinism, which means he gets to dictate the very concept of criticism of Stalin. It means if he does not shut up, he would trip up the moves made by the reformists, and the old guard could point to Trotsky and throw accusations that the reformists were in the same vein as that boogieman. The reformists in the USSR would prefer to run that discussion by themselves, and embody it with themselves, without an albatross. That's my opinion, at least. I think the worst thing in the world for Khrushchev would be for Trotsky to write that he agrees with him.