I was also wondering the same thing. Thinking about the song Kap Kapita, I believe that Alain Mpela made a mistake for not choosing to release a rumba-song instead, when looking how the songs Eternellement and Vita-Imana boosted Fally Ipupa and Ferre Gola. There people on tiktok that claim now that it was predictable that Alain Mpela's career was about to flop since that he hadn't a proper hit-song comparable to the tracks Ferre and Fally released, when being in Wenge BCBG. While they forget the impact and influence Alain Mpela had at that era as chef d'orchestre (1998-2003).
Alain Mpela had difficulties to pay rent and were claiming that JB Mpiana wasn't paying him enough money. There's an extract of it on the cassette about Alain Mpela's departure.
from 3:07 the interview of Zacharie Bababaswe with Maitre Yoka Mpela and Gisele Mpela in 2001 just before Bercy, complaining openly about how Alain Mpela was struggling financially. After Bercy, there was newarticle written that Alain Mpela had left with the PPU's to form BCBG Musica. But it was quickly denied by Wenge BCBG. From 17:15 min after the Canada-trip of 2001, Alain Mpela responding his relatives and rumors about his departure to Zacharie Bababaswe.
They didn't do the same with Bouro Mpela. But I remember that there was an article written about their mother cursing Bouro Mpela for having left Alain Mpela to rejoin Quartier Latin and that the money of Koffi was dirty money.