We are considering a few days in Arles before returning to Barcelona for our non-refundable flight home in late May. If there is a French rail strike, would be able to take a bus back? If we planned on getting back the day before for a 4pm flight, , would that leave us enough time to switch to a bus?
Strikes are not generally announced months in advance. Nothing has been mentioned about an SNCF strike in May. A bus driver strike could be just as likely as a rail strike.
However, you can check with Eurolines about possible bus service from Arles to Barcelona.
Yes you would. But the French rail company by law, always announces the strikes in advance and not on the day of. And as what happened last year not all of the trains stopped.
There is talk of a strike by one of the smaller unions later this month (supposedly a general strike, but that's pretty ambitious). Whether it happens or not is yet to be seen.
There are no strikes announced for May.
This might be of interest
https://www.sncf.com/en/booking-itinerary/traffic/news/strikes
This is the site I've used to keep track of French strikes: http://www.cestlagreve.fr/