They, and to a degree, Motown had evolved by 1969. These two songs reflect that evolution. Well, not so much the first one:
https://www.youtube.com/watch?v=IA-bspSRCXE
BTW, Dennis Edwards, who replaced David Ruffin in the group, was mighty damn good in his own right. He passed away earlier this year at age 74:
Two killer tunes that never got old. My question remains: Where do you get five guys who can sing tight harmony?