tl;dr Article mentions a longitudinal study of this theory but the study was criticised for selective data. Article mentions that Ms Kubler-Ross started resea

tl;dr Article mentions a longitudinal study of this theory but the study was criticised for selective data. Article mentions that Ms Kubler-Ross started researching spirit media and the likes which would have contributed to her decline. Nowhere is it clear that the theory itself is flawed or "fallen". Can someone chime in here please?