All the game classes is based on builds of the D&D players handbook, will be great if the devs create more options to a same core classes, like they did whit Fighert (great weapon and fighter). We will have Control and War Wizard, Fighter and Devoted clercic and etc. In my sight, it is a solid possibilty.
Yes, i think they will, in future, implement many other classes and races because it will be a way to gain some money. But about the end game. What news they will bring to us treating about classes? Do you believe in a endgame without all the classes listed in phb one? I think it is necessary, talking about anything based…