It depends on which wood species was actually used in the knife. Ebonies are from the Diospyros genus of woods, and various species of the tree are used for wood products. One variety used often in knifemaking is Macassar Ebony, which has a reputation for cracking. Other ebonies are more stable and used traditionally in piano keyboards (the black keys), for example. Confusion can be increased because a similar family of wood, African Blackwood, is often called "ebony."
You probably did well in buying the knife, as Laguiole knives (they are made by various firms under the overall name of Laguiole) have a reputation for quality. Keep it clean and out of the elements and it should last a lifetime.