I think that it might be in part due to that Sun Microsystems was bought out by Oracle and though I believe Java will be around for a long time, maybe there is some doubt about in what capacity it will take. I mean to say, new text books will have to be written with all the new copyright stuff, etc.
But I think the biggest reason some schools may be migrating to other solutions such as C++ and C# classes is these two languages are extremely poplular with programmers and probably would suit students' collective needs more appropriately in a standard academic environment.