That was yet another bizarre moment in this story. They were certain Madeleine was dead but couldn't say what they think happened/how they knew. Then the McCanns were apologised to for this. Then the investigators kept chasing CD. It also came out that an ex-policewoman had ruined evidence she'd found and it severely harmed the investigation, and another ex-policewoman paid for CB to be released IRRC.Iirc K&M stopped talking so publicly after CB's arrest. It could affect current investigations. I have some memory they were written to by german police and have stood back somewhat since then.
Here it is 'Since German prosecutors announced they have "concrete evidence" that Madeleine is dead and that Brueckner is responsible, the McCanns have remained supportive of this line of inquiry.' bbc
Could be language barriers and things getting lost in translation but I've found the German/Europe side handling of this all to be a real head scratcher.