Does 'new information' for rewind purposes mean only new mechanical game information (revealed private/secret/derived info), or does it include any information the player becomes aware of about the public game state?

Ruling: New information refers to new mechanical game information (private, secret, or derived information) or a response from your opponent. Simply noticing something about the public game state that was already visible does not constitute new information.

Sequence:

• If you play a unit with no play trigger and no priority is passed, you can rewind since nothing has changed
• If you play something and pass priority, and your opponent passes back, it is too late to rewind
• If you had held priority, rewinding would still be allowed

Nuances:

• There is always some subjectivity in these calls and judges should have discretion for context and corner cases
• At low OPL (Organized Play Level), rewinds are explicitly allowed even with new information to protect newer players from being rule-sharked
• Playing a card and immediately changing your mind (like playing the wrong land) is generally allowed if nothing has changed and no advantage was gained