They've said that multi-classing will be available, yes, but I think they may only have said it once, in one place... and with the way the game is at the moment, it's looking like tall order for the time being.
I fully agree with you that is why I was surprised when they had mentioned multiclassing as there are so many things that need to be fixed. Of course, we do have over a year before the full game is released so a lot can happen between now and then