Subscribers are required to opt-in before the price decrease, or it is only for price increases?

Recently I have read the news of an Update to subscription notifications, according to it, when an auto-renewable subscription price is increased, subscribers must opt-in before the price increase is applied.

So Subscribers are required to opt-in before the price decrease, or it is only for price increases?

Your answers will be helpful.

Ref. https://developer.apple.com/news/?id=tpgp89cl

Thanks

Subscribers are required to opt-in before the price decrease, or it is only for price increases?
 
 
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