You will be able to get the original routing XP credit. Actually you even HAVE TO according to the T&C (see 2.7 in
https://wwws.airfrance.fr/en/informa...-flying-blue):
In the event of a transfer onto an alternative flight due to circumstances unforeseen (and not caused by the Member) the Member will gain XP and earn Miles for the flight originally purchased, and not for the route flown.
Of course AF/KL well-known IT might not do the trick automatically, but if you ask an agent, there will be no issue.