Would be nice but it wont be as simple to add as just a stronger version of an animal.
There needs to be several new mechanics added before any new meaningful enemy can be added.
Jorb and Loftar need to understand every possible cheese mechanic and then figure out how to prevent them for these special animals.
For example there is nothing stopping people from still using palisade traps to solo kill much stronger animals than they are.
Wolves were supposed to be special. In reality they just use the legacy pack mechanic where they attack you together. Its not that special really.
I would first like to see higher tier animals have more unique mechanics and rewards than hope that the new "challenging" animal people are asking for becomes an interesting PvE experience.
I think its a big ask that wont be added any time soon.