This is actually a classic case of Ha Lan Ha Lehu. For the crowd that the Rambam is addressing it wouldn’t suffice not to bring it up, and for those with whom the Raavad associated there is no reason to introduce these patterns of Chakira.
As an aside, the Rambam mentions that the full answer is long and complex with many introductions. At least part of getting the fuller picture is understanding the concept of time being a self contained created reality. This comes with a slew of new questions that have to be addressed. It requires another way of thinking. This is why the Rambam says here that although he can’t get into the whole thing, just keep in mind the punchline, that questions about knowledge are based on our understanding of knowledge and in actuality this does not apply to HKBH.
Put it this way, the conundrum of Parah Adumah doesn’t really eat me up since I really understand Tumah in the first place. Perhaps if I would know what Tumah is all about, and why and how the Parah gets rid of it, the question of Metamei Es Hatehorim would fall away.
Here too, we know that we don’t understand how Hashem knows the future (I mean, He’s not a Navi) and we can’t even define what His knowledge really is, either. Therefore, questions about things that you don’t comprehend don’t apply.