Yes, they are perverse, but my understanding is that they could always be changed despite EU Regulations. They do prevent Refurbishment work becoming zero rated, but there is nothing preventing a reduction to a lower rate. In fact a sensible suggestion that was often put forward was that both Refurb and New Build become 5% rated.
Just another example of blaming the EU for something we could have chosen to do ourselves!
We should also ask what this means for architects wishing to build in the EU. Generally a Free Trade Agreement covers goods but not services. So post Brexit we should be asking what access we will get to the EU? (probably none unless you set up an office in an EU Country) and will our professional qualifications be recognized in the same way? ( probably not, and likely that one will have to jump through many hoops to practice as an architect.)