Not wishing to raise to many temperatures regarding much discussed RTL-GATE but....
If in 99/2000 Diana had recorded a new Supremes album featuring both Mary and Cindy instead of “EveryDay Is A New Day” might things have proved very different.
A promotional tour would have been a natural and they would have had new as well as old Supremes product to promote. Quite possibly a hit single featuring all three women.
Negotiations for a promotional tour would surely have commenced sooner so everyone involved knew exactly what was on offer.
Often [[not always) a reunion tour includes a new album from the reforming band which I think adds additional interest and excitement to the whole proceedings. Something RTL lacked.
just a what if ponder.