"At the time of accession" being the operative statement here. It is easy saying to a new entrant who desperately wants to join the club that you will temporarily restrict movement as a condition (and indeed the UK government had the choice to do so and didn't). Once the countries are members, and have the same right to free movement, and it would take their unanimous consent to remove freedom of movement, it is impossible to remove their rights.
My point was more that it is a bit off for the representatives of countries that did restrict freedom of movement to lecture the UK about it's importance. The UK could have applied similar restrictions but I think that the EU would be in worse shape if it had done, it would be nice to get a bit of credit for this.
