Please remember that this is still a rumor until the official announcement.
via an anonymous source on Faeit 212
I have seen the next issue of White Dwarf, and in it is the announcement for the next dataslate for Tyranids, Leviathan Rising II, Tyranid Invasion. There is not much mentioned except that the story of the world Satys invasion continues, and it also contains new rules and scenarios.
I am imagining since no date is listed, and it says available in its various formats, that the release date will be on Saturday when the magazine is released, or at least available for pre-orders on that date.