This is absolutely nothing to be afraid of, or even give attention, any country can ban anything related to crypto they want, or even crypto in its entire self, but the issue have always been in its implementation.
For example, Nigerian government banned crypto entirely in the whole of the country, but it's citizens still go about crypto like there was or is no ban at all, I believe this will be the same story in Denmark, how are they going to effect this ban? To make sure that citizens don't continue using self custody wallets even after this ban? There is no way to implement such a rule, even if they restrict citizens access to the domains of those wallets, citizens can always use VPN to bypass such restrictions.