The Demon Emperor's speculation is not without reason.
The Immortal Realm's assistance in evolving lower realm demon beasts into treasure beasts must be for some purpose.
If it is to enable the lower realm to have stronger capabilities to resist the Celestial Demon Sect, then it makes sense.
As to why only demon beasts can inherit Immortal divine techniques, the Demon Emperor's speculation is one possibility. Perhaps this plan is led by a great powerhouse of the demon clan from the Immortal Realm.
Another possibility is that the cost of such inheritance is too high, as the number of treasure beasts indicates everything.
On the other hand, the human race does not, in fact, have the same urgent need for such inheritance as demon beasts.
Because the human race is naturally favored by the Heavenly Dao's luck...
The offspring of demon beasts at most undergo bloodline mutation, bloodline evolution, or reversion to ancestral traits.
