Related-Subreddit Auto-Subscription

To increase effectiveness of subreddit branching (eg Occupy Wall Street break from Politics) we could have subreddits listed as related in a subreddit's description or sidebar as they usually are currently... but these subreddits could also appear automatically in subscribers' sublist. If redditors want to unsubscribe from a child sub, they still could by users having sub & unsub list behind the scenes, so the effective subscriptions list would be:
SUBS+CHILDSUBS-UNSUBS=SUBSLIST

This way, branching will cease to exist as a form of censorship, while still allowing self-censorship (the only good kind).

*e: perhaps this could be a preference setting, so redditors scared of having too many subreddits can choose between subscribing to childsubs or not