Does the flashing yellow signal indicate that the green signal is about to come on?

Why?

The flashing amber light in the video warns of danger or an obstruction and requires extra caution. Red and amber showing together announce that green will follow; flashing amber does not.

§ 98 ust. 6 oraz § 95 ust. 1 pkt 4 rozporządzenia w sprawie znaków i sygnałów drogowych