So long as knowledge goes beyond mere true belief, foreknowledge is implausible, since having and relying on relevant true beliefs is sufficient for inquiry. A stepping-stone version of prior true belief seems reasonable, though perhaps we should accept only an even weaker view: a stepping-stone version of roughly-accurate beliefs.
Even if we don't have any knowledge in this life, we have and tend to rely on relevant true beliefs; and that's sufficient for inquiry.
We certainly have to have a view about knowledge in order to decide whether some version of foreknowledge is necessary for inquiry or whether some philosopher or other thinks it is. Roughly, the more demanding our conception of knowledge is, the less plausible foreknowledge is; the weaker our conception of knowledge is, the more plausible foreknowledge is.
The reason we can't attain the highest level of knowledge while incarnate is that we can't then wholly escape the influence of the body (and so of perception and of certain desires that take us away from thinking properly); and that prevents us from understanding fully what forms are, which one must do in order to have the highest level of knowledge.
If historians of philosophy are to be divided into those who focus on discontinuities and those who focus on continuities, I belong in the latter camp.
