All civil servants get paid in the end, including those who were on “vacation” the whole time. If one was planning to do overtime (e.g. to build up hours for upcoming yuntufs) you do lose that. Contractors in most cases don’t get paid.
This is a ridiculous, but largely harmless way, for the Democrats and Republicans to prove their ideological purity. Holding your breath until you turn blue is childish. Giving your employees a paid vacation is an insane from of protest.