An error occurred while saving the commentAnonymous commented
Yes, please "enable" this feature. Even if it's changing the default to notifications enabled for any new channel. I'd rather have users complain about getting spammed with notifications and teach them how to turn them off, rather then have to have everyone "learn" how to get notifications for each important channel.
Most users that I interact with find it counter-intuitive to enable notifications for something they are a part of.