Do hidden cards count as played cards for effects like Ravenbloom, or are only cards activated from hand considered played?

Ruling: Hidden cards do not count as played when you hide them on the battlefield. They count as played only when you later activate them from hidden.

Sequence:

• When you hide a card on the battlefield, it is not played at that moment
• When you later flip and activate a hidden card, that is when it counts as played

Nuances:

• Cards can be played from hidden, but the act of hiding them does not count as playing them