People are only saying Danger De Mort & Everybody are classics simply because the standard and quality of music these days have dropped big time.

For me personally a classic album is if there’s no skippable tracks or at least 1/2 songs I can skip. There’s a lot of albums that become classics due to how it’s aged over time and also the commercial success is a factor as well as long term impact.
Internet by JB Mpiana is an amazing album but as you said there’s some songs that I can skip ( I still don’t understand how they messed up the générique. 
When I look at Koffi his album run from 1990 to 2003 were all classics people debate about Attentat but again that album has aged better over time.

Would you consider A La queue leu leu a classic because it wasn’t as well received compared to Maison Mères previous projects.

Danger de Mort is a hopeless album and in the last 30 years would only consider Ultimatum as a classic album by Koffi. As for Werra, i actually prefer "A la Queue leu leu" to "Operation Dragon". However, the former suffered because Operation Dragon raised expectations to an unprecendent level that Werra couldn't reach. It doesn't help matters that "A la Queue leu leu" was released in Dec, 6 months after the back to back zenith concert where all the songs had already been introduced. Thus, it suddenly looked like old material. In general, like Koffi's "attentat", you release an album and then do a mega concert rather than a mega concert and then an alum with the same material

I think the Bercy concert was on Saturday 22 September 2001, just under 2 weeks after the infamous 9/11 incident in America

Did the concert take place or was it cancelled? Is this the same Bercy that Koffi, Werrason, Papa and JB played in?