while i'm not up on every detail of the Temps history, my thinking is that the timing of David's departure coincided [[though i don't believe it was planned) with the adept and sudden reinvention of the Temps sound and look. Cloud 9 was the first single with Dennis and it was a radical departure from what proceeded it. it was a new sound, the guys traded off lead lines, etc. This reinvention of the group dramatically increased their relevance with the record buying public and this immediately helped smooth over the issue of David's departure.