Consider these three theses:
There is at most one empty world, i.e., world where nothing exists.
Presentism is true.
Something can come from nothing.
By 3, the following should be possible: first there is nothing, and then there is something. But if something can come from nothing, a fortiori it is possible that nothing comes from nothing. Thus, by bivalence about the future, here are two metaphysical possibilities:
There is nothing now, but later there will be something.
There is nothing now, and there will never be anything.
By presentism, if there is nothing now, there is nothing. So, both 4 and 5 entail that the world is empty. But there is at most one empty world. So, 4 and 5 are true in the same world, which is absurd!
Thus, we should reject one of 1–3, or reject bivalence about the future.
Given the plausibility of bivalence as well as of 1, we have an argument that presentists should deny 3.
I myself deny 3, but since I’m not a presentist I deny it on other grounds.