I doubt if airefrance would have time to do a hair test, and then make decisions from that point. It's a good idea, but more for follow-up and to see if anything else is awry.
If there are signs of mercury poisoning, then the supposition was correct, and your back at start with less time. If there isn't, then pulling the Amalgams shouldn't aggravate anything if it is done correctly.
Limited time-frame makes this harder, unfortunately.