The 2019 Challenger Cup participants are clear and the draw for the tournament in Ljubljana, Slovenia, looks like this:
Pool A
Slovenia
Turkey
Chile
Pool B
Egypt
Cuba
Belarus
The event will take place in the week of 3 - 7 July.
Assigning the tournament in Slovenia looks like a cheap excuse by FIVB for every decision they took concerning the WL/VNL format in the past few seasons which directly affected Slovenia. But it's still nowhere near certain whether Slovenia will make it to VNL 2020.