Uhm, there's a lack of correlation between the two; the success of the bands & the gender of the persons therein.
Franco & his O.K Jazz incorporated female voices first in 1972 in Likambo ya Ngana. There's a 1960s inclusion, I cannot however recall the title. Detta, Nana & Baniel made O.K Jazz good music. Female dancers were part and parcel of both Afrisa and OK Jazz from their inception.
Mbilia Bel held Afrisa up for a really big chunk of its existence.
2 of Congo's greatest bands (OK JAZZ & AFRISA) died with their owners, not as a result of female inclusion.
The rest died due to splits, growth of individualism, and personal need for spotlight stardom.