I would be shocked if it ended up being a V10. After all this talk about V8 TT and last of the V10.
If you think about it, the biggest rival already dropped to v6 for the entry level car. There is no need for Lambo to develop 2 new engines (v10 and v12) + hybrid system at the same time. It makes zero financial sense and also unnecessary from a competition point of view. Especially when they have a perfectly good and road approved V8 TT. They will also need to get the v8 + hybrid version approved for the hybrid Urus. Make more sense to keep the same engine for urus and H replacement, add hybrid and get approved and use for both cars.
With Ferrari using V6 for the entry car and V8 for their midrange (baby hyper car) SF90. Lambo will stand alone with a V8 in the 300-400k Supercar segment