Too risky proposition! Retirement fund needs to be stable in return and appreciation. It must not be a rollercoaster ride. I understand that millennials and Gen Z are willing to take risk but that risk appetite will decrease with the growing age. What rollercoaster ride seems to be enjoyable now, might become scary later.
So my take is that, bitcoin must not be a part of pension fund at all. If people want, they can invest by themselves and build a portfolio over a period of time.
Pension funds need to be safe and secured, and investing in cryptocurrencies might certainly bring them a bigger risk of losing their funds in the end. However, with regards to bitcoin, these Gen Z and millennials can always invest in it but with an amount they can afford to lose, maybe a small portion of their funds which they won’t consider a big issue once lose. After all, these Gen Z and millennials are smarter and more technology inclined compared to other generations, so probably they are now aware of the risk that crypto brings.