Yes, this, exactly.

I do nice things for myself not because I have deep-seated beliefs that doing nice things for myself is the right thing to do, but because I feel motivated to do nice things for myself.

I'm not sure that I could avoid doing those things for myself (it might require willpower I do not have) or that I should (it might make me less effective at doing other things), or that I would want to if I could and should (doing nice things for myself feels nice).

But if we invent a new nice thing to do for myself that I don't currently feel motivated to do, I don't see any reason to try to make myself do it. If it's instrumentally useful, then sure: learning to like playing chess means means that my brain gets exercise while I'm having fun.

With cryonics, though? I could try to convince myself that I want it, and then I will want it, and then I will spend money on it. I could also leave things as they are, and spend that money on things I currently want. Why should I want to want something I don't want?