As I'm french (and living about an hour and a half from the park), I've read the project document, and there's a lot to say !
1st, they don't just open a coaster just to say "we have a coaster". It's an educational park about volcano, and all sorts of events like storm, earthquakes and so.
They've about 350 00 people coming to the park each year, and they want to reach the 500 000 goals. So the idea to make it happen is to offer more "fun" as they said. So, they plan to spend 30 millions € until 2031 to reboost the park. The first part will be the coaster, after that there will be a planetarium, and some rooms to make the property a full resort. They also planned to have a tower themed after meteorological events, and a rafting about maelstroms and waters things.
For the 2 last ones, nothing is already fixed, so we don't know for sure what it would be. But, as the park is set into a natural park, les Volcans d'Auvergne (Auvergne Volcanoes), they must reduce the visual impact of the rides, as for the noises. They can't exceed 18m in height, and the rides have to be the quietest possible.
So for the coaster, It WILL be an Intamin, it's official (the name is said in the work schedule), and it will very probably be an Family Drop. The theme will be based on earthquakes. As the coaster leaves the station, you will see a short dark ride, and then enter the 5-meters height drop part. The ride will then hit the launch (top speed of 55 km/h, 34 miles/h) and, except for one big turn with an height of 16m, will stay very close to the ground and the forest.
As I said, they have noises issues. That's why they chose an " electric launch" as they said. Don't know if it would be LSM or just drive launch as the Intamin's MotoCoaster.
For my own, I have a lot of interest for this ride. I've been once to Vulcania and it's pretty cool ! They have an ETF trackless Dark-Ride that is very great for such a small park ! Their skills at theming are quite good, so I hope the ride would be very pretty. I think it would be a great addition for the park.