Doesn't seem like there's an official announcement since any news articles about it describe it as a "quietly discontinuing" [0]
I'm in the U.S. and a search for "oasis" has nothing but eye drops in its top results. You have to scroll down to find a listing for the "International Version — Kindle Oasis", selling at just $135 [1], but which Amazon refuses to ship if your address is in the U.S.
As with all previous kindles, the only official bit is the removal from the store. There hasn't been a case (so far) of a kindle that was removed from the store and then a later model being released.
