Bhāvanā: Kumārila and Bhartṛhari

Bhartṛhari speaks of bhāvanā in his well-known passage about pratibhā (who taught to the cockoo bird to sing? The pratibhā). Bhāvanā should be a synonym of it. The vṛtti glosses it as śabdabhāvanā, since it is essentially linguistic. Abhinavagupta, who surely knew (and sometimes criticised) Kumārila, uses again śabdabhāvanā in the same sense as Bhartṛhari. Is it possible that two so different meanings of śabdabhāvanā co-existed without anyone feeling the need to specify "my śabdabhāvanā is not the same as Bhartṛhari's/Kumārila's one" or the like? I am not talking about bhāvanā, a common name throughout Sanskrit culture, but śabdabhāvanā does not seem as much broadly used (I do not know of other cases of its usage). Finally, could Kumārila have not been aware of Bhartṛhari when he called the linguistic bhāvanā "śabdabhāvanā"? Or did he have it somehow in mind? What are the implications of that?