That is a risk you always encounter in France, and why I would never rely on public transports or trains when there are important time constraints, like the need to get back to a cruise ship before departure. Striking and protesting in the streets is the real French national sport, and the current situation is simply a further example of that. And yet, France is the most visited country in the world.
The only time you can be sure you won't have a problem is if you are visiting during a long holiday, like Easter weekend. The only thing that will prevent the French from striking is the prospect of not taking advantage of a holiday.
(BTW, I've lived there for many years and otherwise traveled the country extensively before and since)