The distinguishing quality of predatory pricing is that it's an unsustainable tactic used to push competitors out of the market before raising prices at a later time. It's not predatory pricing if the price never changes and in the case of YouTube the price to consumers has always been free, even before it was owned by Google.

Not really, with ads the price has changed, you just pay with your eyeball/brain time. From videos starting instantly, to waiting twice for 8-seconds pre-roll (minimum). Or you can pay $12€ / month.