Isn't it usually announced in the October of the preceeding year?
As it's the centenary tour coming up, keep an eye out for a 'randonnee du centennaire'
For the centenary year of the tour on the morning of the final day there was a 'randonnee du centennaire' which was the Paris city loop, done by 10,000 members of the public who had applied to take part (three of whom were MrWC. WCMnr & self). It was a great fun thing to do. You had to apply early in the year and then in June the notifications of having a place arrived.
Started all 10000 of us at the base of the Eifel Tower - did the loop on closed off roads, public gathering along the route cheering us all on. It was an amazing sight, all of us in yellow jerseys cycling up and down the Champs Elysees.. As MrWC & were cycling up the cobbles, WCMnr had already made the top and was cycling down the other side, waving & yelling "Hi Mum!" as he zoomed along. At the end, Jean-Marie Le Blanc greeted the riders as we crossed the finish line.
It was quite magical