The UK will also have to withdraw from the UN convention on the reduction of statelessness
Why so? Doesn't every citizen of the EU have citizenship of at least one EU member state / nation?
Isn't the agreement that EU citizens have freedom of movement contingent on them having citizenship of an EU state? For instance, people working / visiting the UK from outside the EU still need a visa to travel to other EU states.
If someone chooses to renounce their national citizenship, how can they remain an EU citizen without becoming a citizen of another EU state?