Neocore Games have announced that Warhammer 40.000: Inquisitor - Martyr's expansion, Prophecy, as well as the 2.0 patch will be delayed, to July and June, respectively. In the meantime, there is a compendium of planned changes in 2.0.
Warhammer 40.000: Inquisitor - Martyr was a less than stellar action RPG which mostly comes down to badly designed progression and combat that is anything but fast and smooth, both of which ARPG fans have come to expect after Diablo 3 and Path of Exile.
Neocore Games are aiming to rectify those issues with the upcoming 2.0 patch which will also bring the Prophecy expansion. Unfortunately, the initial release date for the patch will be pushed to 20 June 2019, which happens to be just after E3 2019.
While that wait is not something fans will like, the wait for Prophecy will be even longer. The standalone expansion will not be out until 30 July 2019 so those who played through enough of the base game will have to wait another two months until they get new content.
On the other hand, 2.0 is not that far way, just over three weeks. There will be plenty of changes and it appears Neocore put together a compendium that lists them all in one place.
The highlights are most likely the new combat and progression systems, both of which have been improved. Combat flow should feel much better with quicker, more polished animations and a general decrease to global skill cooldowns. In essence, there will be much more skill usage without derpy animations in quicker combat loop.
One of the major gripes we had with Inquisitor - Martyr is that we couldn't access inventory during missions, which is an Anthem-scale failure. This will be changed in 2.0 as well.