When kaolinite clay [al2(si2o5)(oh)4] is heated to a sufficiently high temperature, chemical water is driven off?

Yes.

Explanation:

Below 100 °C (212 °F), exposure to dry air will slowly remove liquid water from the kaolin. The end-state for this transformation is referred to as "leather dry".

Between 100 °C - 550 °C (1,022 °F), any remaining liquid water is expelled from kaolinite. The end state for this transformation is referred to as "bone dry".

Please note that throughout this temperature range, the expulsion of water is reversible: if the kaolin is exposed to liquid water, it will be reabsorbed and disintegrate into its fine particulate form.

On much higher temperature than the above stated transformations are not reversible, and represent permanent chemical changes.