That's my personal opinion too. There is no need to hurry. They know, that they brandmarked him for life. No german prosecuter does that on purpose, if he/she isn't sure, the suspect is the one they're looking for. That needs much more than a simple verdict!
There's also a possibility, that the MM'case is already investigated for a safe charge. BKA investigated it since 2017, HCW since 2018. That is a lot of time for one single case IMO. But i assume, this investigation goes further, according to other victims.
If HJG's statement to the Neuwegersleben evidence is true, than even to give that knowledge to him, is also tactical behavior. As far as i know, not even SY and PJ got info about the crucial evidence, HCW claims to have. So maybe the investigation has gone on further in that way, that speaking about would not harm it anymore. Who knows...
I always get my hopes up in this case that MM will get justice and her family can get some peace and closure, but I really hope you are right as I have faith in this lead and the German LE too. Just because it’s quiet right now doesn’t mean behind the scenes it is. HCW said to the Irish independent newspaper that there has been progress. He is just playing safe as they don’t want to lose CB and want to make sure he is behind bars!