After this laws implemented, now Spaniard who want to value their privacy about their Bitcoin need to use Tor, Bisq, Bitcoin mixer and other things that make sure the centralized party e.g. government, internet provider, banks can't track their Bitcoin holdings. But this will be considered as illegal act and broke their laws, so anyone need be careful enough.
Centralized exchange without KYC can still track your IP logs and your real name, you have no way to hide.
as no other tax legislation has gone this far.
I think any tax legislation had been like this before, you're need to report anything that involving about capital gain or source of income.