Just saying -

The First's predilection toward Light is suggested to have been a consequence of the Thirteenth's collapse into the Void.

Hydaelyn giving Crystals of Light to her chosen on the First isn't implied to have affected this at all.

The Flood of Light was not planned for; that was an unforeseen consequence of Ardbert not playing his part to perfection by sparing Cylva and turning his wrath upon her Ascian masters. It was, however, taken advantage of by Emet-Selch.