Well, if it counts the EEs, than the numbers are not that surprising. It is also no longer saying much, sicne we have a game that got multiple re-releases back in the day and then a new version a decade later, which is also released on multiple platform, 6 if I count correctly.
I think Larian *can* get as many as BW did with DA:I. Will they? Not sure, but they do have a realistic chance.
I personally see the EA as an improved version of a Preorder and there are *always* people who will wait until a game is launched. Also, for someone who is *not* into BG or D&D, why would they buy this game? When it is released and they hear or read good things, they may become curious though.