My thoughts on the canon updates: I'd suggest two time restrictions.
If it's a standalone product like a movie or video game of a series (current examples, Marvel movies and upcoming Kingdom Hearts), restrict to 3-4 weeks, so similar to current canon wait period. This follows the original idea in which it's substantive content that requires more time and resources to obtain.
If it's episodic, like a chapter or episode, 1-2 weeks. These should be more easily accessible and spoilers less of an issue because the product is more immediately consumed.
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If it's a standalone product like a movie or video game of a series (current examples, Marvel movies and upcoming Kingdom Hearts), restrict to 3-4 weeks, so similar to current canon wait period. This follows the original idea in which it's substantive content that requires more time and resources to obtain.
If it's episodic, like a chapter or episode, 1-2 weeks. These should be more easily accessible and spoilers less of an issue because the product is more immediately consumed.