The president of the Paul Ricard race track has said to French magazin L'Equipe the French that the track will change for the next French GP.
https://www.lequipe.fr/Formule-1/Article/Stephane-clair-le-trace-va-changer/815635

http://www.skysports.com/f1/news/12433/11010144/f1-2018-will-halo-introduction-cause-teams-to-miss-winter-testing?utm_source=t.co&utm_medium=referral

FIA

After Imola in ‘94 Max (Mosley) formed the Expert Advisory Group. McLaren lent us a chassis, and we put a dummy in it, and crashed it in various directions at the MIRA test facility, to get data about what was happening to the head and chest. We learned that the seat belts stretched so much that normally the head hit the steering-wheel – or, in a lateral accident, the side of the cockpit.

Because of that, we introduced the high cockpit sides for 1996 – and every team except Ferrari complained to me about it! I’m always singularly unimpressed when people say a safety measure is expensive. One team principal said to me, ‘You’ve cost me a million pounds, to change the chassis’, and I said, ‘Well, knock it off your driver’s salary – it’s for him, not me...’

It's money and time they'd rather spend on winglets and vortex generators.



Plus ça change...

So since we're all very concerned of the drivers safety, I think it's safe to say that the safest approach for the coming season is to simply not have halo until we have enough data of it. And when it comes to being certain of safety features I don't care how many more years its going to take for the necessary simulations and data collecting, halo must not be rushed in and thus risk drivers safety.

How much data and research would satisfy you? The same researchers have been researching various potential structures since 2011, including halo, and have concentrated on halo since July 2016. They simulated (at least) 23 distinct incidents from this year back to 1995, using both the known data from the actual incident, plus modifications allowing for slightly different parameters. They explained their methodology in detail, and directly answered the most common criticisms. This isn't a knee-jerk change. It isn't a tyre chicane, nor is it knockout qualifying.