That's not strictly 100% true, more like 99% maybe
The Leica badge jobbies do have tweaks to their processing pipeline so they have at least tried something different, plus I'm pretty sure that Leica must have had some input on lenses, how much though we may never know. Might just have been a sign off.
I'll go with 99%

Maybe the conversation went something like this.
Ring ring, ring ring.
Herr Leica: Hello Pano-San, my new best friend. Good to hear from you, things are pretty tough here in Leica Land.
Pano-San: Yes, they are. That's excellent news. We though we could sell a few more cameras if we made people think they were Leicas, and give our brand some credibility.
Herr-Leica: Oh fantastic, we could put a big sensor in it, and make some nice fast primes, charge £5k, and, and... we'll both make a fortune.
Pano-San: Who's this 'we'? And there is only a modest budget for this.
Herr-Leica: How modest?
Pano-San: Very modest. Like zero. What can we do for nothing?
Herr-Leica: Well, paint them battle-ship grey and put a red blob on the front. Mess with the software and take the handgrip off.
Pano-San: Our software is very good - why mess with it? And won't taking the handgrip off make it harder to hold? And what's this red blob?
Herr-Leica: If you mess with the software, we can claim it's different, and different is better in Leica Land, and better means we can charge more. You've got to take the handgrip off to make it harder to hold, more like a like proper Leica - people have to suffer for their art. Art is worth paying extra for.
Pano-San: Ah so! What about the red blob?
Herr-Leica: The red blob is everything! It's worth a fortune!
Pano-San: Okay, we'll make it bigger then?
Herr-Leica: Nooo! It's gotta be small! We even charge more when we leave it off completely!
Pano-San: We thought that was just a manufacturing error! Now are you up for this or not?
Herr-Leica: How much are you going to pay us?
Pano-San: Well, we thought it should be in line with your contribution to the development and production costs.
Herr-Leica: Not very much then!
Pano-San: No, but it's more than you're getting now.
Herr-Leica: You gotta deal!