It probably does not make sense to you how God could be all-knowing because God is not subject to logic.
I think he has to be, because likewise as they mention in the video, we don't assign logical contradictions to God, so God follows these as well. Meaning God couldn't create something he couldn't lift if he is all powerful.
But I don't really think this is an issue anyway. If I should argue the case from your side or at least from your perspective, I think it is possible for God to have perfect foreknowledge, without actually "violating" the idea of God. But there are some things which would still be true, free will for us wouldn't exist in that case.
Also im far from 100% certain that this would be correct from a logical point of view, because we are working with some concepts that are extremely complicated to get ones head around and what exactly it would mean, such as infinite and outside time and space etc. But maybe someone else here can find flaws in it, nonetheless its will be a fun thought experiment.
Obviously we have to make some assumptions and guesses. But the way I could see it being possible is due to several things, first of all because the Universe is a closed system, meaning that all matter stays within the system, but simply changes form. Like water turns to snow and back etc.
God would know what the state is for all matter in the Universe, what state it will turn into at any given point in time etc. whether it is going back in time or forward. Which would, as I see it, also mean that he could have perfect foreknowledge of everything about our Universe. Which would solve that issue at least
But then we still have the issue of God knowing everything about himself as well, but I think one could argue that this is solved by God being infinite and outside time and space.
If something is in the state of infinite, I think one could argue that there is no past, beginning or future it is simply the state of being and I think most religious people would agree to this about God's being.
Time also wouldn't exist, because the state of infinite can't have a beginning and therefore no end either. So God wouldn't have a future, nor a past and therefore it would be a logical contradiction for God to know these things about himself. Which means that God doesn't break any logical rules as such from being all knowing, but again, this only applies or make sense in regards to our existences, not God's, because he is infinite and therefore the future is infinite as it has always been and will always be and have never had a beginning or changed at any point.
But again it wouldn't solve the issue with the lack of free will for everything in our Universe, that would still apply.
Again, im not 100% certain this would hold up logically, but for right now, I think it would be a valid argument for how God could be all knowing without being logical inconsistent, if one is willing to give up free will. But maybe someone can tell me why that wouldn't work?