[seebs]

I don't think that follows.

I don't think anyone would argue that knowing a thing after it happens makes it non-free.

Our usual intuition informs us that, if two things are causally connected, they have to have some third common cause, or the one that happens first has to cause the second... but I think that if you include the future in "omniscience", that this also admits the alternative answer that time is just completely broken. The knowledge is determined by the events, the same as it would be for anyone else's knowledge about events, it just happens out of order because apparently deities do not respect linear time.

But the inexorability of "what happens" and "what is known about that happening" being the same doesn't imply that what happens is determined by what's known, and indeed, I think usually it's the other way around; the knowledge is determined by the reality.