Wrong again - you're making a habit of this!
"Free movement rights can be restricted under EU law if: for discriminatory or distinctly applicable restrictive measures, a derogation ground expressly provided for in the TFEU can be engaged; for indirectly or non-discriminatory, that is, indistinctly applicable restrictive measures, an overriding requirement relating to the public interest that is capable of justifying a restriction of the fundamental freedoms established by the Treaty can be demonstrated; and in both cases, the restriction also satisfies a proportionality test, that is, it is both appropriate and necessary for achieving the relevant public interest objective."
Thus something that can be justified/negotiated!
Or in a simpler form for some
https://www.theguardian.com/world/2016/jul/24/brexit-deal-free-movement-exemption-seven-years
"Plans to allow the United Kingdom an exemption from EU rules on freedom of movement for up to seven years while retaining access to the single market are being considered in European capitals as part of a potential deal on Brexit.
Senior British and EU sources have confirmed that despite strong initial resistance from French president François Hollande in talks with prime minister Theresa May last week, the idea of an emergency brake on the free movement of people that would go far further than the one David Cameron negotiated before the Brexit referendum is being examined."
'Non negotiable'?