This coaster really intrigues me, and I wonder what to expect here. Given that RCDB is right and we're looking at an Intamin coaster, there are at least some existing coasters to compare with. Let's go through the stats of some other Intamin launch coasters, just to see if they are similar enough to say something about the layout. We'll call the coaster "Unknown", just for the sake of easy comparison (because "The new coaster for Linnanmäki" takes too long to write out).
To start with, here are the stats of Unknown, out of RCDB:
Length: 1,104 m
Height: 52 m
Speed: 106 km/h
Elements: LSM Launch
This gives it a length slightly longer than iSpeed and Soaring With Dragon (980 and 1050 meters, respectively), but shorter than Taron and Maverick (1320/1356 m). Both of the latter have dual launches, though, and I've got a feeling that Linnanmäki would have said as much if their coaster was getting them too.
As for height and speed, Unknown is slightly shorter and slower than iSpeed (which is 55 meters/120 km/h), but slightly taller and faster than Nefeskesen (50 meters/100 km/h) and Superman Escape (40 m/100 km/h). Soaring with Dragon reaches 60 meters/125 km/h. It is taller but slower than Storm Runner (46 m/120 km/h).
A top hat after the launch seems likely, as Linnanmäki does not have that much room to build on. The ride being replaced, Vonkaputous, is barely 330 meters long, and they barely have a stretch of land 100 meters long to build on. Launching into a non-inverting loop seems out of the question, as there simply would not have been room for it. The land does have an L shape, though, if a lot of trees are chopped down. The terrain isn't flat at all on the site.
See for yourself.
Another coaster that matches interestingly well is Volcano: The Blast Coaster. At 112 km/h and 47 m tall, its stats are within 10 % of those listed for Unknown. Still, if an inverted coaster was on the table, wouldn't the park have marketed that first and foremost? Also, there might be a good reason why Intamin suddenly stopped making inverted coasters (or at least, that parks stopped buying them), which is another argument against it.
So yeah, I predict a sit-down coaster with a single launch into a top hat, followed by some twisty and compact layout. The terrain is too rough for it to be a clone of anything, it has to be specially designed for the site.
Can't wait to see more details!