Gaga's numbers, as well as JT's sound about right.
Lorde will be lucky to sell 100k
Miley shouldn't do less than that with 2 smashes.
I have a little doubt for Eminem considering Berzerk is not really big enough to give its album that number but I won't underestimate him.
Too soon for Gaga to tell, this prediction can go terribly wrong in both ways, it can either be lower according to what will happen till then, or way higher. Too soon to tell, and with Gaga this time around things are constantly changing.