In the same way that it doesn't matter if you rigged the lottery or just got lucky ?
Rigging the lottery is not arriving at a supposition; it's creating a reality.
I don't think anyone in the debate is considering whether a problem of free will exists because God creates the future as He would like it to be. Because obviously such a universe would lack free will and there would be no debate.
It isn't about being right on occasion. It's about being infallibly right. And guesses aren't infallibly right.
The intensified version of being right on occasion is being right on all occasions, not being infallibly right.
One's guesses may be right on all occasions even if their guesses are just guesses, and having been 100% correct in all past guesses does not necessitate the next guess being accurate.
In other words, being a good guesser—even a really good guesser—does not make one incapable of error, even if one has thus far not erred.
The OP asked how foreknowledge and freewill could coexist.
Discussing the potential deficiencies of the common pop-philosophy understanding of knowledge is not an act of ignorance or error, but spot on the topic and (seeing as no one has offered a fully agreeable solution) probably not a waste of time.