D&D has mutated and changed a great deal over the years, originally there were only three classes: fighters, magic users, and clerics.
Yup...I will still always think of both original blue box and original "Advanced D & D" so all these variants and proficiencies and weird tweaks are ... not exactly D&D to me.
As for how much will the game change from now/early access to full Launch? Don't know. But the few folks I have known that have participated in "Beta" type stuff haven't ever reported huge changes.
I enjoy this game...I'll likely enjoy whatever it turns into.
