That is one of the most idiotic things I have read. Obviously it's not impossible to travel for them anymore, but freedom of movement referred clearly to the rights of free movement between EU States as a citizen for Work, Education, Travel and Business

Obviously they can still travel to Europe, but they will need an ETIAS Visa Waiver in the future, instead of just going, they can't move for work and studying just as easy without applying for Visa/Permits and they don't have the same rights and access to services as Citizens of a country.