Decentralized currencies are legal (outside of Turkey)? How is that an utopic assumption?
I expect stronger condemnation towards "anonymous" cryptocurrencies (Monero, Zcash et al) and making onboarding/offboarding for them more difficult, but that's about it.
I don't see that happening anymore. There's too many startups with too many smart people working in the space and a LOT more people (including the legislatures) invested in Crypto.
But, if you believe otherwise as a capital market participant, buying and holding Bitcoin is a fine play to back such a belief.
History suggests that won't last forever, but it probably won't be COIN shareholders or activist hedge funds that forces a regime change as big as that.