Although the trademarks for Sun and Moon were discovered before the special 6 minute Nintendo Direct, Nintendo was able to confirm the release window of Holiday 2016.
For retailers, securing a pre-order from customers is the number one priority, and right now 3 major retailers have both Sun and Moon available for purchase.
The dates haven’t been confirmed, with retailers citing it as a December 31st, 2016 release. (December 31st is commonly used as a placeholder when retailers are unsure of release dates.)
With this being the 20th year of Pokémon, you can expect some big deals coming your way regarding the new games. The pre-order may be tempting, but you can always buy from the eShop if need be.