If CB is convicted of murder but not abduction then it can't be assumed that he was an abductor. How Madeleine left 5A would remain a mystery for ever. Maybe MWT's theory was correct; she wandered off.
If the evidence results in Brueckner's conviction for Madeleine's murder it negates absolutely the slurs Amaral and his band of sceptic followers have been promoting for over fifteen years.
The mere fact that there is evidence which makes Brueckner the prime suspect already does that. But there are too many egos invested in the beliefs promulgated by the nasty theories Amaral dreamt up, aided and abetted by sceptic ignorance for common sense to prevail.
Madeleine's ultimate fate might be determined in a German court; and that will not be a forever mystery, only why you should record that opinion for posterity remains in any which way mysterious.
Even the most rabid of sceptics require to justify the ill begotten path they have travelled by choice. Even the most hardened of sceptics appear to have realised the need to excuse their unquestioning active support for the dregs of humanity as exemplified by the new folk hero whose criminal behaviour and convictions brought him to police attention in the first instance.