Stalin was almost universally loved and worshiped among the not-yet-jailed population. [EDIT: "almost universally" is stronger than necessary to make might point. The real numbers are not known and hard to come by. "A majority" would probably be a safe estimate.] But you do have a point that after his death it could have unraveled, though not necessarily so. Mao is still venerated in China, and Kim Il Sung in NK. Besides, narcissists are skilled in convincing themselves that everyone loves them, except for bad people. So I don't think your argument that
Stalin had hoped to someday use cryonics, he would have had to be a less ruthless ruler.
has no basis in fact.
Stalin was almost universally loved and worshipped among the not-yet-jailed population
This is plain not true, the level of his popular support (not "love and worship") is disputed, but at the "more than half" vs "less than half" level.
But I kind of agree with your conclusion.
This month's media thread includes a short article on some people's idea to have Ayn Rand frozen, which ultimately didn't happen. My first reaction was a shudder. I thought, I definitely wouldn't want Ayn Rand preserved forever. My second thought was, What right do I have to say who can and who can't get frozen?
Whatever your thoughts on Ayn Rand, I think this can spark an interesting conversation: What, if anything, should humankind do about people who are widely seen as harmful for the whole? For example, if the Castro dynasty in Cuba or the Kim dynasty in North Korea decide to freeze themselves to ensure they will continue oppressing their countries forever, should that be prevented? (And yes, my opinion of Ayn Rand is such that these examples came to mind.)