The end was actually scheduled for April 2020, but the coronavirus lockdown caused a two month break and extended the project to June.
According to the German media, in total 20,448 i8 were built. So far, there is no direct successor for the i8 announced.
In Leipzig, BMW produces also the BMW i3, which resumed production in May and already returned to pre-lockdown levels (116 units per day, single shift with an option for 250 at two shifts).
The i3 is confirmed to stay in production until 2024 (it's not known what will happen then).