After listening to that, I thought that this might be a feature of AmE. However, I listened to the BrE and AmE pronunciations of thrive, jive, alive, drive and hive; I noticed it only in the BrE versions of jive and hive and tth AmE version of drive. It seems to depend on the individual speaker.
Where this devoicng occurs, it will be noted in a narrow phonetic transcription of an individual's speech, but is not appropriate in in phonemic transcription (between two slashes, /.../).
This post-release feature of stops is generally known as aspiration. It is not associated with fricatives such as /f/ and /v/The “voiceless ə-like sound” I said sounds like /h/. You can hear it clearly in words ending with /p/ /t/ /k/.