Comic-Con saw Marvel Comics tease a new Annihilation event, and now thanks to Amazon, the details for Annihilation Agenda have become known.
According to the listing for the trade paperback, Annihilation Agenda is described as:
The Negative Zone is under siege! Now the Lord of the Negative Zone, Annihilus, makes a call for help to the very heroes he once fought against! It's an all-out battle as Nova, Silver Surfer and some of your favorite cosmic heroes try to prevent the next annihilation.
It's noted that it collects ANNIHILATION (2019) ALPHA 1, A1-E1 and will be released March 2020.
Comic-Con saw the Annihilus teaser released teasing, "Annihilation was only the beginning," for November 2019 with Donny Cates announced as the writer.
Update: Donny Cates is not confirmed as the writer, per Cates' Twitter.
We see the new Annihilation is sort of opposite the original 2005/6 story where Annihilus invaded our universe, with the cosmic heroes coming together against him. Now Annihilus' own world is being invaded by some unseen force, with Annihuilus forced to get the help from the Marvel Cosmic heroes including Nova and Silver Surfer. We can probably assume the Marvel Cosmic heroes aid Annihilus because our universe would be next.