The 43% mortality drop is a purpose score among older people living in the community. It is not a retirement effect.
The page then treats leaving work as what collapses purpose, and purpose as what kills. Those are two studies glued at the word "purpose." Rohwedder is memory after exit. Boyle is a questionnaire. Neither is "the whisper starts shutdown."
Boyle's sample is community-dwelling older persons, not a working-versus-retired contrast. The 43% figure can be true and still not tell you what labor-force exit does.