Based on other forum posters' reactions whenever leaks happen, I have a feeling this opinion of mine is unpopular:
I love preview/reveal days. The more information is revealed, the happier I get. If enough spoilers are revealed, it's pretty much Christmas in July(/actual month of reveals/leaks) for me. Then my imagination takes over, testing cards/etc., making decks/teams, analyzing how good the new content is, etc. (yeah, some of these are Magic: The Gathering-related).
(Pokemon Ultra Sun and Ultra Moon leaked today, so I'm swelling with happiness here.)